I say that because, as I mentioned earlier, the Stonehorn Dignitary scenario is one in which, if we think a card might be an issue, we axe it instead of thinking too much about it
This means no one is safe as long as you have Mulan leading the charge
Offering a potent Mill effect, insane stats, Annihilator, and a devastating Ward cost, Ulamog, the Defiler is utterly brutal
Toil / Trouble Toil is a good draw two effect that black usually has access to in cards like Read the Bones and Sign in Blood
And since it has those symbols, it has the Five Color identity, which limits it in Commander, but it is very strong as a leader, and with every card to choose from that's been printed, this should dig pretty deeply into your options