Shadowverse

Cthulhu was nerfed even further.

They promised not to mess up individual crafts.

Promising doesn't mean getting married. Blizzard also promises a lot of things, but still, in Hearthstone, one or two classes regularly emerge that are noticeably stronger than others (hello, Druids).

They trimmed the Acidlord.

I read it that way. There's a monster like that in Godville.