Yeah, for whatever reason, Cruel Ultimatum just doesn't excite me. Nicol Bolas is more likely to land and I think has more play to it.
The problem with
Nicol Bolas is that the power level isn't really there, for his high casting cost and colour commitment. At eight mana, you want something that really stabilizes the board, like what
Terastodon does, whereas Nicol Bolas just... casts
Control Magic. I've been a part of and witnessed multiple other games where the caster lost the turn immediately after casting Bolas.
On the other hand, it's much harder to lose within a few turns of resolving
Cruel Ultimatum, between the
Drain Life, the
Diabolic Edict, the
Raise Dead, the hand clearing, and the card draw. It produces way bigger swings and has a much larger board impact, and for one mana less.
vs
