The reason for the wild late game is simple: I was playing Necropolis against Solmyr. The landscape favored me, and Wokial was shredding bones even on the red spawn point. In the end, when Solmyr had nowhere else to go but to run to my main base, I couldn't resist upgrading all my angels and, with the Crimson Sphere (and a cloak), I finished the game.
Thanks to my opponent for the match and the advice for the future: don't let Necropolis reach the late game, especially if the opponent is a mage.
