@Cire: immediately -3 Mystic Sanctuary, add 3 Daze, then make room for a 4th Daze. Question with Foil becomes what you're pitching that advances gameplan by virtue of being in the yard (or madness-enabled). Secondary to that, you're playing a lot of blue and you're going to have to answer a lot of questions with your remaining slots. You have to be able to either not care about or stop C. Priest, RiP, Choke, Narset - and this is just the short list.

You have ~12 slots left, and you need an instant/sorcery-based CA engine. You need a way to win the game. That way to win the game has to be reliable against things like Depths and Vial. Your deck has to reliably survive until turn 4 (but really, turn 5) and prefer playing long games.

UB Mill is probably a better launching point, but even this deck has Islands on board issues as they will play more aggressive land counts with GQ/Field of Ruin. They do at least have this idea of Archive Trap turning on Visions of Beyond, and Sanctuary picking up either piece of this synergistic combo with value stapled on.