Caster of Magic II Spellweaver idea

[Seravy]

A different way to approach this :

Once during your game, you can select a spell that would not be available to research, and add it to your researchable spells list.
(You can only choose spells from tiers you are able to learn based on your spellbooks, and the added spell uses normal rules for appearing for research after it has been added.)

This way, no matter how many realms you play, you get exactly one additional guaranteed spell - but you get to choose which after you already know the spells you rolled. You still need to roll one of the spells in a combo and have to discover the combo yourself - and the best, it's a temptation to use it up on that one important common or uncommon spell you missed so it's not even trivial that it'll be a rare or very rare spell.

[teelaurila]

I'm restarting with COM after being away for a year or so, so perhaps some of my info is out-of-date. But:

One of the simplest "I win" buttons was, at least for me, magic immunity+spell lock + runemaster/specialist. Because of fortress-busting.
If spellweaver guaranteed magic immunity with 3 books, sorcery runemaster+spellweaver could take life or death for an easier start, and still be all but guaranteed their win button.

If multi-realms are presently under-powered somehow, allowing for extra guarantees to get those combos sure is a way to boost them. Since early game is always what really counts for me, multi-realms don't seem weak. But perhaps it is just my style of early win or bust.

[teelaurila]

Another point here would be that spellweaver likely could do with some extra oomph.
As it is I would only consider taking it as life barbarians. With any other build, alchemy+archmage would be preferable. Either I'd want the alchemy to boost my units, or the archmage to help with summons.
Again, with the caveat that mostly I focus my builds to early and mid game, as I can win higher difficulties (master) only when winning early.