I made a post opening up my character to any interaction. As for matchups, Lyall would best work with another XYZ user. It's technically possible for him to work with duelists who use the other methods of special summoning, but in that case it is highly recommended that they be able to summon their key monsters early on.

[@Eklipse] I once dueled a KOSS user... 5000 attack King... wow....