In a similar vein to Xantcha, Sleeper Agent, this legendary creature makes an opponents creature an active detriment to their board state, and it incentivizes them to pay 3 mana to get rid of it and give the rest of the table a card
Raff, Weatherlight Stalwart Raff, Weatherlight Stalwart is one of the more unassuming creatures on the list as a measly 1/3 for but offers plenty of card advantage and a mana sink in the command zone
Its pretty easy to include a fair number of good Demons to the deck to make that a possibility, especially if Blood Speaker is searching them up
ANCIENT ADAMANTOISE Hard to remove, protects you and your board from damage, and drops treasures when it dies
You must also reveal all face-down spells and permanents you control if you leave the game or if the game ends
Ancestral Anger is great when you can run all four