mtg bringer cards of the BLACK DAWN, Fifth Dawn: MTG/ At the beginning of your upkeep Witch-king, Bringer of Ruin ·

These provide you essentially an alternate win condition while also improving your mana

I stopped the skid at diamond tier 4 with zero wins by switching to Rob's version of mono blue(plus X1 negate plus Dive down x1 minus x2 Mist merfolk unblockable guy)

Captain N'ghathrod Zareth San, the Trickster Gisa and Geralf Sheoldred Reanimate Arcane Theft Animate Dead Bonehoard Invasion of Amonkhet Cards that utilize milling

It wasn't easy to pull off Sliver Queen, but you certainly got paid off in return with an endless supply of tokens that would have whatever extra abilities you'd care to scrounge up if you felt the need for them