Cards like Arc Trail and Dromoka's Command which are some of the more common removal spells to get two for ones with at two mana are unlikely to hit high value targets and are both rather dependent on the right situation
Top cards: Emrakul, the World Anew (~$125 borderless foil), Ulamog the Defiler (~$85), Nadu Winged Wisdom (banned in Modern, Commander powerhouse), allied fetch lands
Neither mode is particularly impressive, but pairing both on a single card makes it an interesting silver bullet for decks that might need answers to threats they cant otherwise handle, like Ketramose, the New Dawn
It also at least adds a chance that you take out your opponents threat since you already know your blocker will be destroyed
This opens up a horrifying possibility: There are a non-zero amount of games of cEDH in which youll just kill yourself with Necropotence
Landfall Whenever a land you control enters, Choco gets +1/+0 until end of turn