I wanted to play cards that are on their own good without relying on Hero.

While Grief is an awesome card, he won't improve our board state without a Hero, so i cut him from the pool at some point.

Hooru Pacifier is for example a better card for the board, but i cut it aswell after some thinking, because we have enough Flying already. Overwhelm would be a nice ability for Hero, though. The problem is that our curve already has many 3-drops, so i cut it, although it might be a mistake, because Pacifier is really good. Without Grief we only have Stonepowder Alchemist + Makto for Revenge and if i would cut Alchemist instead of Pacifier, getting Revenge on Hero would be really difficult, but maybe we don't even want Revenge on Hero, because of Dark Return + Scream.

Thanks for the question! Made me think a little more about the deck.