Undead are clearly overpowered here... Fear+freeze are best combo against ninjas, and they also have best range AND burst when enemy first approaching. Compared to this - orcs and demons doesn't worth it.
And to those who can't kill ninjas - 5x fireball that does 400 dmg will kill anyone. Just max your mana pool and reduce cost/increase power of fireball. Again - fireball is only good spell worth mana spent. Cutting trees is, uhm, "technical spell" that used 1-2 times/level and frenzy is too costly/not affecting damn ninjas.
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