can't really compare mxy and lt imo. were mxy in marvel he would certainly be below lt as his dimension (and all the dimensions above and below his own) would all be under lt's jurisdiction. since he's outside lt's power....
as far as protege--ridiculous character, nonsensical arc. unclear why scathan could deal with him but lt SEEMED unable to. if i had to pick here, i'd say protege SHOULD be able to copy myx's powers, which really wouldn't=win, but likely eternal stalemate.
I don't want to lowball LT, he is like Spectre im my book. Anyway, wasn't LT like unable to defeat an Korvac from another reality and wasn't he owned by a gun made by reed from another reality and was he not powerless against the Beyonder (a cube being, pre-rec but anyway, he was always a cube being after the rec)?
So Mxy and LT have their share of "low" feats but honestly, Protege > LT was pis. I don't like it, though I can accept it, it was a low feat of LT and not his best day. He still is < Mxy.