Notes & Combos
Build can definitely be improved, for instance if I had enough UR, I'd use Odd Eyes Rebellion XYZ Dragon as a target for Supreme King Magician instead of Crystal Wing Synchro Dragon (since you can actually make Rebellion in a pinch).
Melodious as an engine for this deck has its pros and cons, if I could I'd definitely use SHS instead, as Ostinato is really the only card insane card from the engine, but its overall still great off ostinato alone (side note: never scale couplet, you don't want to be locked into light when the deck is almost exclusively dark lol)
All in all, a serviceable (though not exactly optimal) way to play the deck.
Remember, pend deck is best deck!