In case of that, if you using heroes based on magic skill, you need more mana to more and more to using the magic skill.
In the latest HoMMs all the best abilities for heroes is always in might heroes with some spell like Mass slow, blind, hypnotize, mass bless and mass haste.
As for the new abilities that didn't exist in the previous HOMMs, Reinforcements I is crazy good. If you cast this on the stack your opponent most often targets at the start of combat it is the easiest way to come out the battle with no loses. Because your opponent still targets that creature and you only lose the reinforcements.
