There are cards, Buys, money and trashing, so something could be done with KC. It's the kind of set I expect Marin could work wonders on.
Restricting to BM, Vaults would have been useful and were probably the strongest opening on 5/2. Mandarin has a cute interaction with Venture in that topdecking Victory cards or one of a set of Ventures, but isn't as strong as Vault.
PPE: s/marin/shark_bait/g