Polluted Cistern // Dim Oubliette (Death Toll Commander precon card) Polluted Cistern is cheap enough to drop early and start applying pressure, so it's already playable enough from that point alone
While it's exiled, its owner may cast it for rather than its mana cost.) Whenever you cast a Lesson spell, Aang gains lifelink until end of turn
For example, a deck can play many Blood Artist lookalikes, many Persist creatures, multiple ways to generate +1/+1 counters on them as they ETB and of course many sacrifice outlets
So far, most Summons have been massively high-powered, splashy, and downright fun cards that make a huge impact on the game both as soon as theyre cast as well as during each of their powerhouse chapters
I looked for a used one on Ebay and found one for about $60