As a fan of the Black Knight myself I would be over the moon for him to even be an echo. I don’t think his super heavy build would mean that he is impossible. Not at all. It could make him quite unique as a sort of tank of a character. Thinking Little Mac but with an unbelievable amount of armor that will brittle down as the fight goes on.
Besides. Although he’s played out to be a hulking, absolute monster of a tank in the Radiant games it’s more of an aesthetic choice of his own because as the Black Knight and as Zelgius it’s been shown he is quite nimble in cutscenes even fully armored. Chasing down Ike or taking down the speedy cat Laguz Ranulf kind of proves that his slow movement is more of an intimidation technique by him more than anything.
Besides. Although he’s played out to be a hulking, absolute monster of a tank in the Radiant games it’s more of an aesthetic choice of his own because as the Black Knight and as Zelgius it’s been shown he is quite nimble in cutscenes even fully armored. Chasing down Ike or taking down the speedy cat Laguz Ranulf kind of proves that his slow movement is more of an intimidation technique by him more than anything.