This is exactly what Draining Whelk does, and the fun only begins if you get to pair it with blink effects like Ephemerate or Ghostly Flicker
Its also a testament to the inherent explosiveness of the sacrifice playstyle that almost any value-adding trigger quickly becomes game breaking when coupled to it
It may not be the most expensive Magic card ever sold, but it stands as one of the hardest to obtain
Ajani, Outland Chaperone I didnt want to put this at number one, but I feel like its just so subtly good
For example, if Strata Scythe's imprint ability ("When this Equipment enters, search your library for a land card, exile it, then shuffle.") triggers twice (probably because it somehow entered attached to Cloud), up to two total land cards can be exiled
A lot of modern planeswalkers, like the new Ugin and Elspeth from this very set, do have passive abilities that will continue to function while Conqueror is out