Im not sure Aether Channeler is quite as big a role player as Callous Bloodmage, but its still a flexible piece for Wizards, flicker decks and Human tribal
The main disadvantage that Oswald Fiddlebender has is that he needs to stick around so he can tap to activate his ability, but you can rapidly chain things together to set up a combo or try to lock things down
Any kind of permanent can be hit, from artifacts to lands, making this card an answer to whatever your opponent is up to
For the design of the character I tried and mixed different parts from all sorts of Phyrexian creatures from Magic history
Often just a removal magnet, if the Mentor can stick around for a few turns, it will take over the game
In recent years, top-down design has been used to great effect in worlds like Theros to connect them to their inspirational concepts in myth