Which faction do you like the most?

And their magic is the strongest, regardless of the school.

Since when on earth do they have the most powerful magic? Of course, if you upgrade the super-ability, they can cast all spells—that's cool. But otherwise, for Warlocks (and Necros, for that matter), spell power develops much more strongly. When it comes to chaos magic, Warlocks are simply beyond competition. And a Warlock will summon a stronger phoenix (if nature magic is upgraded) than a Mage would. For some reason, Mages focus not on spell power, but on knowledge. Now, they truly have no problems with mana. I once tried to develop chaos magic for a Mage, and compared to a Warlock, it was such garbage that I even wondered why they were called Mages in the first place.