Oni Ronin is a Unit.
How to Get Edit
Play him as early as possible and buff him up. Oni Ronin will reward you with a large bonus from Warcry Warcry:
When this attacks, the top unit or weapon of your deck gets +1/+1. and damage beyond your wildest dreams.
Created By Edit
Was one of the first known cards from the game (along with Hellhound (Beta)).