Just played AoS in a game with Ogres vs. Deamons. My buddy learned that his herald can summon a unit of pink horrors that can then summon another unit of pink horrors in the same hero phase, and so on. So you can summon a unit that can then summon a unit without end. He brought in three units in one turn. And he left the rest of his deamons at home, or he could have summoned even more units.

He simply beat my Ogres by attrition. There was no way for me to eliminate all his wizard units before he whittled down all my Ogres.

It totally sucked.