It takes some work, but you can cast Instants and Sorceries out of their yard, and with Tasha out, casting one of their spells using anything, not just her -3 ability, nets you a blocker (It's a 3/3 demon but, trust me, it's a blocker)
At minimum, you get to draw an extra card and make an extra land drop, but the upside is much higher than that
Similarly the factions of Chaos are combined in The Ruinous Powers deck, with daemons and Chaos Space Marines fighting side by side
, : Creatures your opponents control attack this turn if able
However, it also meets fans highest expectations, not just in terms of the strategic depth, but also regarding the quality of the cards
7 Con #2: Selling Them Yourself Takes Time If you decide to sell your cards yourself, then you best be prepared to have them sitting around for a while