This looks like a lot of fun! If you're still trying to figure out what colors to run, I'd say you definitely need white and black, since most knights are either of those. If you want a knight as commander, then abzan with Sidar Kondo would be best. However, I think Tymna the Weaver would be a better choice than Ravos, since she combos better with Sidar Kondo. If you really want to, you could add red or blue or both, but that seems like a bit of a stretch.

Yeah, Ravos kinda nonbos with a few things like Mentor of the Meek and Sidar himself but I love the recursion aspect. Nothing Phyrexian Reclamation and Palace Siege can't fix though.

And don't forget Haakon!