Spellweaver

[Nelphine]

Edited to add something about pick value.

Oh, that's true. But still, compared to conjuror which does the same, it still feels underwhelming for 2 picks when compared to conjuror.

[Seravy]

I edited mine as well with the reply meanwhile.

[Nelphine]

Ehhhhh I'd argue the opposite. No matter what you have, until you have armies, you can't win. Even if you get spell of mastery 10 years before your opponents, if you don't have the ability to defend while you cast, you lose.

Summons are inherently the basis by which everything is compared. That's why casting a buff that costs the same as casting a summon, is always worse. You don't put focus magic on your ghouls, until you have a stack of 9 ghouls. You don't put lionheart on your chimera, until you have a stack of 9 chimera.

Summons are better, no matter how versatile everything is.

(And in general, everything else has a limit on how many you can cast. But summons, you never have enough summons; not ever.)

[Seravy]

I'm not saying summons are worse.
Yes, summons ARE better, in general.
But if your premise is "I'm not playing a strategy where I summon a lot" then you'll benefit more than a summoner would when "I'm playing a strategy where I summon a lot".

Basically, Conjurers will still use like 30-50% of their skill on non-summons (city buffs, economy spells, enchantments, unit buffs on the summons, whatever needed), but Spellweavers will only use like 0-10% of their skill on summoning, if any - if they play their strategy right. Sure, if you go buffs you might still want one, or maybe two unicorns. (or angel or archangel) But that's it. For the entire game. If you go peaceful, you might want a stack of 9 very rares for your fortress before SoM. But again, that's it for the entire game. (ok maybe one more stack for lair hunting. Maybe. But your heroes and combat spells can take care of that, so probably not.)

Needless to say, for a generic strategy, Conjurer will be better 75% of the time, but there is still that 25% when your summons fail to work (Sorcery wizard killing or stealing them all or whatever) and this helps literally everything else you can do.

(In my current game, I actually had no use for summoning for like the first 15 years of my game. The summons I did have were literally unusable against Holy Word, and prior to that, I was making werewolves which is not a summoning spell. So even though I was going for a generic strategy, Spellweaver would have helped me, Conjurer, not.)

[Nelphine]

Fair. All right.

[Seravy]

Done. Just looking through my spellbook to test the effect makes me feel this is going to be pretty useful and powerful as is. 
Next : AI.

Do we want the AI to cast more nonsummoning spells if they have this retort? I think yes? Easiest way is to reduce summon priority, so everything else gets selected more. So if we want them to do 50% more nonsummons, then we need to reduce summon priority by 33%.

Now, default wizard picks.
Life wizards get 24 spells that get reduced in cost by this.
Nature gets 19 but the AI can only use 18 of those.
Sorcery gets 20.
Chaos gets 14.
Death gets 16.

So every realm has uses for the retort, Life is clearly the best, Death is actually second worst and most definitely the worst for gameplay (more curses!). Also, Chaos+Nature wizards pick this as their secondary. As both are summon heavy and we probably don't want to encourage Chaos wizards to do more curses either, we should move it from here as well.

[Seravy]

I don't think I can fit Spellweaver as a primary retort for any template but we don't need to. Not every retort appears as primary.
Death could get Cult Leader as primary - no template has that right now.

We could drop Artificer from Life/Sorcery and add Spellweaver there. That leaves us with no Artificier template however so I'm not a fan of it. So I don't really see a place for Spellweaver in the secondary template either.

Chaos/Nature seems a good place to have Conjurer as secondary as both realms get very scary summons. Spellweaver actually isn't a bad one here - since they still get the same amount of summons, but do get more economy (and destruction) spells. Chaos endgame spells are casting cost heavy (Call the Void, recasting globals) and Nature does get a very rare buff, the only one in the game (Regeneration), and both realms benefit from the boost at uncommon level a little (more change terrain AND transmute AND raise volcano at no loss of summoning potential). So I guess this can stay as Spellweaver then.

For default human wizards, Spellweaver on Death is still good. Encouraging human players to use curses is never a bad thing, and cheaper werewolves and drain power can also make these potentially overlooked spells get played more.

[zitro1987]

Pretty good retort solution - quick overland casting of non-summons. I figure it works best with mono-realms + specialists as it means most spells will cost about half.

[Bahgtru]

A +10 pop grow speed bonus for each unit of garrison?

Ah, the retort names would be hilarious :D

I was considering some trade bonus gold thing but it would step on the toes of too many races.

Actually, it'd synergise with some races well, what do you mean with your comment? I like this idea.

[Bahgtru]

Pretty good retort solution - quick overland casting of non-summons. I figure it works best with mono-realms + specialists as it means most spells will cost about half.

The mono-specialist AI is already the biggest problem there is at high difficulty. Well, mostly for summons, but life would get a huge bonus with this and it doesn't need that at all, it's already the scariest one. Every single unit megabuffed would make for a quite annoying game.