Vexing Devil

In Commander, Vexing Devil is a niche include rather than a staple — the opponent-chooses clause is most punishing at low life totals, and 40 life gives opponents comfortable room to pay 4 without flinching, so the card only pulls full weight inside a dedicated trigger or recursion engine. In Legacy and Vintage, it sees fringe play as a one-mana burn threat in aggressive shells where four damage on turn one can close games, but it has largely been eclipsed by threats that don't hand the opponent a decision. Modern tells a similar story: powerful enough to see occasional play in Burn, but the format has no shortage of cleaner one-drops. Vexing Devil is not legal in Pioneer or Standard.