Good removal, or other fun cards.
Acidic Slime is a catch-all
Everflowing Chalice it's 0, but you can pay the kicker after you cascade into it. Maybe useful?
Mulldrifter and Shriekmaw can be evoked and the cascade will use it's full mana cost.
Bear Umbra seems almost like an auto-include. I see a lot of times you can't get full value off cascade because of mana shortages.
Eternal Witness goes in(almost) every green deck. Greenwarden of Murasa may be better (it's a lot cheaper) for you for cascade purposes.
Brainstorm before ydriss attacks and you can set up your cascades.
Dig Through Time is great, high value cascade ...and i have extra copies
Noxious Gearhulk i love every time i cast this card.
Puppeteer Clique is cheap, and it really can hose graveyard shenanigans, exiles the creature at EOT (end of turn)
Command Beacon is a card to look out for. Helps when your commander gets expensive.