@warriorg how is it absurd if the Author already lazily and blatantly creates an OP MC? It's literally just creating one existence that can Thanos Snap the protagonist's plot armor away-yk, that thing the writer can do at any point they feel like.
Where does this existence come from? Who cares? Like the MC, just say that it is so. Pop it into existence just cause.
The MC isn't OP anymore, oh no...so anyways-
The MC is a walking Deus Ex Machina who already kills the story, so we'll call it even.
Because the MC is a big FU to the foundation of the World and the nature of the Character Arc, and such a god like character to actually check their place would put some damn balance into the Story while perhaps even adding a sense of risk and stakes.
Rimuru lives in a fantasy world that constantly gratified him, screw em.
Don't know Moonlight Walk, but I would like you to define
challenge. Had to many people use that word in the absolute wrong setting.
You can have Antagonist who naturally scale to the Protagonist. They don't have to End Bosses, yet, just naturally advantaged against the Main Character. If it turns out the MC is
already a walking God, then I don't see the problem in the End Boss showing up early.