There are so many ways to try to combo off with Bolas's Citadel, whether thats various kinds of storm decks in Modern, Jund Citadel in Pioneer, or that deck youve seen in Historic with Bartered Cow and Refurbish
It works with everything from cards that were in Standard at the time of printing (Living Death, Recurring Nightmare) to strategies recently printed (Boneyard Wurm, Spider Spawning) and everything in between
He can be in play by turn two with a little ramp, and while the food token from his +2 ability isn't that impactful, he's then sitting at six loyalty - and dealing with him is an utter nightmare
This will cover you
Modern Horizons 2 feels like a love letter of sorts to MTG
You dont even have to play a Voltron-style deck either, you can take a page out of Eriettes book and load your deck up with auras that negatively affect your opponents