Lots of stuff would die to your Fire Imp that they had cast on turns 1 or 2, so you could stamp out stuff like Soul Warden, Birds of Paradise, Priest of Titania, and more
Gemstone Mine has come back as recently as Time Spiral, but its a confusing enough card that I doubt well see it again soon
Ruthless Technomancer also serves as a good inclusion in a deck looking to harness these effects, as it will actually convert your sacrificed creatures power into Treasure tokens that you can save for a later turn, or simply cash in for an instant speed reanimation effect
It's so strange, and I'm kind of sad that there's absolutely nothing in its name or its nonexistent flavour text to tell me what a Tetravus is
I play Farewell in some of my own decks, but I always try to include a way to come out on top when casting it
The cycle was later completed in Commander Legends so all 10 color pairs have access to one