A bunch of people have done some really great review of the different Lores of magic in 8th edition, so I don't want to do a bland Lore by Lore review. There is, however, a missing picture that most people haven't thought about, and that is synergy.
Now there are two types of synergy and I'll cover them both. First will be covered in this article, and it is the synergy between multiple Lores on multiple casters in one army. The second is the role of magic in creating a synergy with your list.
So let's get into it. Pack a lunch, this will be a lengthy one.
Most folks play between 2k and 2.5k. Yes, there are some armies that can bring two level 4's with full access to two Lores. But for the most part, people will be playing with a level 4 and a level 2, and that is the assumption I'll be making for this article.
Since spells are random, we can safely assume that the level 2 will have the signature spell from that lore, since it's assured and you can make plans based around that. The other random spell is just a bonus that sometimes becomes useful.
What I will do is go through the 8 signature spells, and detail how they interact with each other lore that will be used by your level 4. Let's get to it.
Fireball - Lore of Fire - Magic Missile Str 4 d6 hits. Can be boosted to have longer range and more hits.
Fire - Fire is a lore, thanks to the innate ability, that gets better when working with other fire wizards, especially for lower level casters. If you have a level 4 with Fire (why?!) taking a level 2 also with fire isn't a horrible plan.
Beasts - A level 4 with Beasts is based around one thing: turning into a big, bad monster and/or casting Pan's Impenetrable Pelt on buff with the army. The magic missiles in the lore are rather weak. You can cover that weakness by bringing multiple level 1 fire wizards with Fireball. Once your wizard transforms into a Mountain Chimera, you'll have plenty of dice left to spam Fireballs each turn.
Metal - Not much synergy here. Metal already has good direct damage in Searing Doom. Fireball is redundant, and adds nothing to your list if you have a level 4 of Metal.
Light - In a lot of ways, Shem's Burning Gaze is superior to Fireball. That doesn't bode well. If you have a level 4 of Light, a minor wizard with Fireball won't be adding much to your list.
Life - Life doesn't have great direct damage spells, as your might expect. Most Life wizards who roll Awakening the Wood trade it for Earth Blood. If you have a Level 4 of Life, there are other Lores that synergize much better with it than Fireball.
Heavens - Heavens has some great utility and some great direct damage. However, all the DD spells are expensive. A level 4 with Heavens could get some mileage out of a level 1 or 2 with Fireball.
Shadow - This lore has no real direct damage spells, so there is an opening for Fireball. Especially if the Level 4 casts Withering and then two level 1s blast that unit with Fireballs. There is some synergy with Withering, but for the most part, armies with Shadow don't need to do their damage with magic directly, since Shadow supports the shooting or CC of the army.
Death - Now this is decent synergy, as much as you can get with Fireball anyway. Toss a Purple Sun with the level 4. Fill up your power pool again. Since most of the rest of the spells in Death are short ranged you need something to do with all those dice. How about casting decently long ranged pumped up Fireballs with a couple of level 1s? Not saying this is the best plan out there, but it can be a nasty turn 1 alpha strike.
Summary- Fireball has a surprising amount of synergy with other Lores, considering how basic and non-subtle a spell it is. I think the Death plan is the best, but I could also see it working very well with a Lore of Beasts plan.
Lore of Beasts - Wyssan's Wildform - Target unit gains +1 Strength and +1 Toughness until the start of your next magic phase.
Fire- If your army has a level 4 with Fire, I'm not sure why you'd take a random level 2 with Wyssans Wildform outside of a very specific list, in which case, wouldn't you take a Level 4 with Beasts? A level 4 of Fire means you plan to do serious damage to your opponent in the magic phase and this is a close combat buff. Pass.
Beasts - Obviously, this combos well with the Lore of Beasts as you might expect. The Lore is full of buffs designed to make you a badder baddie in close combat. I think the best use of this spell in a Beast Magic based force is to throw it on a chariot after the charge. The extra strength on the impact hits and the extra toughness will make the chariot a bruiser, and suck out some dispell dice prior to your level 4 becoming a Chimera.
Metal - This combos very well with Metal. A Level 4 of Metal is based around three main spells: Final Transmutation, Enchanted Blades, and Glittering Robe. Wyssan's Wildform combos extremely well with Glittering Robe and Enchanted Blades. Generally, speaking Glittering Robe is great in armies with weak armor. If your Chaos Warriors or Brettonian Knights already have a 2+ armor save, going to 1+ isn't going to blow anyone's mind. But Wyssan's Wildform on those units makes them scary. Throw the Enchanted Blades on them, and they become monsters.
Light - This Lore also focuses on close combat buffs. It has it's direct damage and utility (in the form of the excellent Protection of Pha) but the offensive combat buffs are the bread and butter. Wyssan's is also a close combat buff, and whereas Light buffs initiative, leadership, attacks, and Weapon skill; Wyssans does strength and toughness, which are always welcome additions to the close combat party.
Life - Compared to Wyssan's synergy with Metal and Light, this one is somewhat of a sleeper. The only thing Wyssans adds is +1 strength. That's a yawner.
Heavens - Heavens is based around direct damage, with a few combat buffs. The combat buffs are relatively weak, and having a guy running around with Wyssan's isn't going to suddenly turn any tides in a Heavens based list. Very similar to Fire in that regard.
Shadow - Ah, now this is interesting.Wyssan's works extremely well with Shadow's debuffs, and it does it at the signature spell level. Shadow's debuffs work well with both shooting and close combat, Wyssans is basically for close combat. If your army is more CC oriented than shooty, Wyssans will work very well for you.
Death - Death has two of the best close combat debuffs in the game already, Death and Darkness; and Soul Blight. Generally, Death magic has a lot to do in the magic phase, and it's hard to see how Wyssan's fits in there doing something unique. Generally, pass here.
Lore of Metal - Searing Doom - Magic missile that wounds inverse to your armor save and doesn't allow armor saves.
Fire - Fire has some pretty good magic missiles. But they are relatively low strength. Searing Doom is strong against all the units that Fire magic is generally weak against. It can be nice addition to the offensive suite. And hey, if your other spell is enchanted blades or glittering robe, all the better.
Beasts - Once you turn into a Chimera, a direct damage anti-armor spell is pretty tame.
Metal - As usual, it synergizes with the rest of the Lore quite well. Being able to pack two copies per army means that against lists with high armor, you can vaporize a unit per turn, and generally those units won't be cheap.
Light - Light buffs and direct damage are decent, but much like Fire they don't really scare high armor armies. Str 4 hits don't scare knights. Searing Doom scares knights. So this can fill in a gap in the offense.
Life - Metal in general works pretty well with Life, as they are very similar Lores. If you're going to bring a level 2 purposefully for some direct damage, to compliment your Life suite, you might as well bring Searing Doom, but I wouldn't.
Heavens - Searing Doom doesn't really add much to Heavens that it didn't already have. I wouldn't highly recommend that combination.
Shadow - Shadow debuffs are pretty great as we all know. But there is no great direct damage in the Lore, and Pendulum and Pit of Shades are expensive and situational. Searing Doom covers two niches at once that Shadow lacks, direct damage, and anti-armor. Searing Doom plus Shadow magic isn't an oh my god homerun, but it isn't bad, either.
Death - This one is just bad news. Death magic is already all about ignoring armor damage. Searing Doom gives you more of what you already have. Sometimes that's good, sometimes that's really useless. There are better lores to couple with your Level 4 of death.
Lore of Light - Shem's Burning Gaze - Magic Missile with str4 d6 flaming hits. Can be buffed to strength 6.
Fire - Shem's Gaze adds very little to a Fire magic brigade. You have to ask yourself why you'd add a level 2 of Light instead of another level 1 with Fireball. Unless your only opponents are undead or daemons, you shouldn't. And if those are your only opponents, why aren't you running Light on your level 4?
Beasts - Similar to Fireball. Beasts could use a good direct damage spell to cast after you morph up. Shem's is better in a lot of ways than Fireball as a one off. It does similar damage, but has the ability to do extra to Daemons or Undead, always nice. Plus if you have tons of dice, you to bump it to Str 6 to kill Hydras and HPAs.
Metal - Doesn't do anything for you that more Searing Doom wouldn't do better. Pass.
Light - The best reason to take a level 2 with Light when you already have a level 4 with it is to make sure your level 4 gets the spells he needs, as two copies of it aren't as good as two copies of Searing Doom is to a Metal list.
Life - I've said it before, Life's gameplan is usually based around close combat or Dwellers Below. Shem's doesn't add anything to that gameplan you need.
Heavens - Heavens can use Shem's because it does need a simple direct damage spell, as the good ones in the Lore are expensive. But I can't see anyone actually making a list where this option is better than others.
Shadow - Unfortunately, Searing Doom tends to do this better. With one exception: killing monsters. Having the ability to pump it to str 6 means your fear of Hydras and HPAs goes down drastically. This is a metagame call. However, remember that many armies that can take Shadow can't take Light, so it is a limiting factor.
Death - This is one case where Fireball is distinctly better than Shem's.
Lore of Life - Earthblood - The Wizard and his unit get a 5+ regeneration save.
Fire - Fire magic wants lots of Wizards in a magic bunker casting lot's of Fireballs. Good magic bunkers need a ward save of some kind, since they will attract shooting. This has a pretty decent synergy, actually.
Beasts - Pretty good here, if you run a shootier army. You can buff toughness army wide easily, and giving a unit a regen save means you will be able to out shoot most enemies in an attrition battle.
Metal - Not a bad combo with Glittering Rob, but otherwise, meh. Wizards who cast Earthblood don't want to be in combat. Metal buffs want to put you in combat. That is pretty much the opposite of synergy.
Light - Much like Metal, Light wizards cast buffs on combat units. Earthblood is a defensive unit buff. Not really good synergy.
Life - Can you believe the intense synergy with Throne of Vines? I can. Plus, it's not too bad with Flesh to Stone, either. Problem is, your level 4 already has it most likely. You don't need two copies of it in the same magic bunker.
Heavens - Heavens is a sit back and shoot lore. Earthblood makes you want to sit back and shoot. Sounds good to me.
Shadow - Now this is a good combo, thanks to Smoke and Mirrors. The Shadow wizard being able to change places with the Life Wizard means that you can get the regen save where and when you'll want it, rather than being in a backline unit. This is good, good stuff.
Death - I don't see anything especially synergistic about giving the wizards unit that screams "wow this would be good with Death magic" but maybe I'm wrong.
Lore of Heavens - Ice Shard Blizzard - Hex spell that gives -1 to hit in shooting and close combat. Shooting attacks that don't use ballistic skill need a 4+ to be used.
Fire - No combo here. In a Fire heavy list you have to have a great reason not to add more fire. This is not that reason.
Beasts - Shutting down 50% of a warmachine's effectiveness can help your Mountain Chimera last a lot longer. Not a bad thing to have when your Mountain Chimera is your main offensive strategy.
Metal - Again, halfing the effectiveness of a single warmachine is ho-hum for most Metal lists. The -1 to hit and -1 to shoot is more relevant for them. But better than double Searing Doom? Nope. Not when you have Glittering Robe, too.
Light - We have a winner. This, plus Pha's Protection is super duper fly. If you are going to go magic bunker crazy, this is how you do it. Level 4 with Light. Level 2 with Ice Shard. Go ahead, shoot my Slaan with your cannon. After you make two 4+ rolls. Oh you're going to charge the Temple Guard instead? At -2 to hit? Good luck winning that! One of the best combos in the game.
Life - Nearly as good. A typical High Elf Phoenix Guard Life Bunker has a ward save and doesn't need regen from Earthblood. But they do need the -1 to hit and protection from strong throwers. This is it. A very good idea.
Heavens - Not surprisingly, a Lore that is focused on sitting back and shooting getting a great defensive tool. It's especially good in non-bunker lists. Being able to have two mages with it in two units shitting on two warmachines makes your list really defensive. Have you ever wondered how Empire gunlines could possibly beat Dwarven gunlines in a shoot out? Now you know.
Shadow - If there is a drawback to Ice Shards, it's the short range. Smoke and Mirrors buddy. This combos ridiculously well with Miasma. Declare a charge, "stand and shoot." "Ok since you have Miasma and Shards from last turn, you hit on 8's. Good Luck!"
Death - Generally speaking, Miasma from Shadow does what this does for Death but significantly better.
Lore of Shadow - Mystifying Miasma - Hex Spell that gives -1 to your choice of Init, BS, WS, or Movement. Can be buffed to affect them all.
Fire - Broken record time, Fire wants more fire. Unless you have a really good reason, add more Fire.
Beasts - Shadow works well with Beasts. Beasts are good at buff your units up. Miasma is good at knocking them down. Miasma is very versatile. The knock to BS is very defensive making the horde of xbowmen hit on 8's is nice. The knock to WS is very offensive. Your unit hitting everything in the game on 3's is dope. The init knock means your buffed units smash first. The movement means your buffed unit gets the charge off. This is all good stuff that heavy Shadow lists do, but with Beast buffs you can work both angles nicely.
Metal - These go together like PB&J for the same reasons as Beasts, but with the added benefit that Metal has better direct damage spells to add to the buffs. Win/win.
Light - Pass here. Light magic already buffs your WS and Init. And defends you from shooting. You don't need Miasma here.
Life - This comes down to how your list is constructed. Magic bunker? Go with Ice Shards. Buffing combat units like Lion Chariots and Sword Masters? Use Miasma.
Heavens - No real synergy with Miasma beyond Miasma's general awesomeness. You can do better. Like a second copy of Ice Shards.
Shadow - More betterness. Combos well with Penumbral and Pit of Shades, ofcourse. But also makes your other debuffs more effective.
Death - Oh this is good stuff. Not only are the debuffs generally useful, but Death is short ranged. You don't want your Level 4 Death magic in charge range, even to cast a snipe spell. Snipe the BSB, cast Miasma somewhere, bring your Death Lord back to safety. Wins.
Lore of Death - Spirit Leech - 12" contested Leadership roll. If you win, loser suffer unsaveable wounds equal to the difference. Can be buffed for more range.
A snipe spell on a hero level guy, usually leadership 8, isn't going to set the world on fire. Repeat this statement for all the Lores except...
Death - The combo with Doom and Darkness is strong. The other snipe spells in the Lore can't compete with how nice that is. It's the bread and butter with the Lore.
Whew. Now that was long. I'd love some feedback.