[[Tainted Indulgence]]

I believe the juice is worth the squeeze on this card. 2 Mana instant draw 2 is above rate and there are a few cards in the format that are fairly good on their own to turn this on - namely:

[[Shark Typhoon]]

[[Hieroglyphic Illumination]]

[[Into the Story]]

Cycling is a good way to get a higher CMC card in the yard at a low cost. Some control lists all ready play either [[Consider]] or [[Opt]] and while HI is worse at U, it's not that much worse (meaning it's not that far off of being playable without Tainted Indulgence; you don't want to play bad cards to make good cards good).

Into the Story is likely an under-played card in the format, however, it does have a pretty high bar to clear. This is the biggest problem in the lists I've come up with. There's really no ideal card to turbo-charge [[Drown in the Loch]] and [[Into the Story]]. If someone can crack this problem I think the sky is the limit here. At best when Into the Story is not castable it can be discarded to the first Tainted Indulgence and later flashed back with [[Torrential Gearhulk]], but the floor is basically un-castable. Seeking feedback and testing. It's likely you cut Into the Story and play something else, but it's so tempting.

The 1 CMC slot is fairly easy - [[Fatal Push]], [[March of Wretched Sorrow]] either discard or more removal like [[Disfigure]]. You could play Consider as well, but not 100% there.

The 2 CMC slot - [[Negate]], [[Drown in the Loch]], [[Tainted Indulgence]], plus some additional removal / counters ([[Eliminate]], [[Censor]], [[Parasitic Grasp]], [[Heartless Act]], etc.)

The 3 CMC slot - [[Sinister Sabotage]], [[Brazen Borrower]], .... could use additional suggestions here. I've settled on 4 Sinister Sabotage and 1 Brazen Borrower right now. There's Planeswalkers, but ideally you don't want them to go to the graveyard ([[Narset, Parter of Veils]] / [[Liliana, the Last Hope]] / [[Kaito Shizuki]] - he's in my SB atm).

4 CMC slot - [[Languish]], [[Hieroglyphic Illumination]], could also use potential suggestion here.

5 CMC slot - [[Ashiok, Nightmare Muse]]

6 CMC slot - [[Shark Typhoon]], [[Torrential Gearhulk]]

7 CMC slot - [[Into the Story]]

Until I can play with the card, I suspect the first cast of Tainted Indulgence is merely a card-neutral loot and all additional copies are draw 2's. 0 ([[Fabled Passage]], Takenuma, [[Fetid Pools]], etc.), 1, 2, and 4/6 is fairly easy assuming you draw the cycling cards.

Why this over UW control. The two reasons are cheaper CA, more flexible 2 CMC reactive spell [[Drown in the Loch]] and higher ceiling / lower floor bomb CA in [[Into the Story]]. I actually think the control mirror is UB favored because of Tainted Indulgence, discard, and [[Kaito Shizuki]]. (Plus you're playing more Shark Typhoons which help a lot)

I think this will be a lot worse against the cheap artifact/enchantment reliant decks like RB Anvil because Portable Hole and March of Otherworldly Light are so good against these decks.

I'm also unsure how playable the other GY MV/Threshold cards are. Newsie being 3/3 Lifelink is way above average for UB, but the question is how fast can you get there, same with the UB Aven Heartstabber. Both of these cards would only be SB cards, but I don't think they crack the 15. Newsie does self-mill which helps...Anyways, curious if anyone else out there has been thinking how to build with [[Tainted Indulgence]] in a control shell.