Ajani, Nacatl Pariah / Ajani, Nacatl Avenger comes down as two bodies for 2 mana, which isnt the worst rate, and if you can trade off the Cat token you get a nice little planeswalker
Then there always the threat reduction staples of Galadhrims Greeting, Elronds Counsel, and Woodmens Clearing
Razaketh, the Foulblooded Well, we know the last of the four Demons Liliana will have to kill will (likely) be a 9-mana 9/9 Demon
Unfortunately, ramp is the kind of strategy that is either going to be great or horrible
Still, there's a lot of pressure on your opponents to keep Riku off the battlefield because if they don't, he can take over games in a heartbeat
It is slightly worse than Growth Spiral, since you can only play a land from the top four cards of your deck, rather than taking one directly from your hand and putting it into play, but still very good