Erayo was just never really interesting. Very easy for the players to avoid flipping it, and the Bolas deck essentially never does.
Archfiend of Despair was a bit too strong. The game the Bolas deck cast it just felt unwinnable (and the deck is already reasonably hard).
Sanguine Bond requires a choice from the Bolas deck. That's a no-no.
Massacre Girl has a pretty unique effect, and wiping the board is pretty good for the Bolas deck. Plus, a 4/4 menace isn't embarrassing.
Dreadhorde Invasion seems perfect for the deck. I almost considered just replacing
Bitterblossom for price reasons, but decided that the redundancy was pretty cool.
God-Pharoah's Statue is a win all around. Obviously, it is a slam dunk for flavor, and it attack the player's spells, which is something the Bolas deck doesn't do much (it mainly focuses on hands and life totals). All around a perfect inclusion for the deck.
Revision 4Added/removed cards:
-1
Archfiend of Despair-1
Erayo, Soratami Ascendant-1
Sanguine Bond+1
Dreadhorde Invasion+1
God-Pharaoh's Statue+1
Massacre Girl