Before I pulled Siphi, I used Black Knight as a Defensive Tank Support. To my knowledge, Black Knight's A2 is the only skill in the game with 100% uptime on Inc Def.
Since I see some similarity between The Knave & Black Knight, this is how I might try to use him if I had him.
That said, I am totally skipping this Deck of Fate. Running Shogun & Mino.
There is one more...it's a 3 turn duration on a 3 turn CD...he was a fusion...my brain isn't braining...swear it starts with a B...it doesn't start with a B but it was Iron Brago.