Sorry for the delay!
I would say in your defined categories: humiliation masochism >> submission masochism >> physical masochism!
I find it very exciting to feel immoral pleasure because of his heightened pride!

I think Suzy and Kirby are the best characters to dominate Meta Knight!
Susie is especially suited for “submissive masochism” and likes to create a clear hierarchy over Meta Knight! (This setup is very heavily influenced by one person)
Kirby is suited to all masochisms, and I think he is good at controlling Meta Knight through emotion!