What are the best cards to put with Olivia in a modern build

I don't think there's a tier 1 deck out there that features her, but my sense would be to slide her into the Jund lists that people have been running for a while (Goyf, Lily of the Veil, Bob, etc). Either that or you could build your own Rakdos build to which I'd say, let your imagination go wild.