Tactics for playing against a Necromancer.

a) No spells are needed in the guild: summoning elementals is automatically added to the hero's spellbook when the "Fire Warriors" perk is acquired.

b) You won't need a lot of mana: 30-40 will be enough (don't forget about spiritual connection on your or enemy units). The "Magic" stat increases primarily for Necromancers, so there won't be any problems with that.

I have priority upgrade paths, for example - Magic Attraction in Education, Plague Tent in Machines, Fire Warriors in Summoning, etc. In practice, to prepare a strong rushing hero, I need level 15-16!