Since this deck is mono-colour I strongly recommend Nykthos, Shrine to Nyx.

Worldslayer also seems like something you'd want with an indestructible general :P

Duelist's Heritage also seems perfect for your deck.

I think this deck would be better with Rune-Tail as commander.

KorandAngelsThank you for the upvote!

I have tried several commanders for this deck, and found Konda to be the best for that this deck wants to achieve. He is harder to remove in my local meta due to the indestructibility, and the vigilance is a nice bonus. While this is a samurai deck, it ultimately boils down to equipping many things onto one single creature. Konda is great for that. I found Konda to remain on the board for much longer and achieve much more than any other legendary creature in the deck. Rune-Tail is a great card, but not the correct commander for this deck. Konda also fits thematically as the commander.