And for good reason: this is easily hands-down the most competitive commander from the set, and the most competitive decks usually end up being the most popular ones too
Neither of them is Balduvian Horde, which hilariously was the card that players back in 1996 thought was the most broken because a 5/5 for four mana was super far above the curve for creatures of the era, even with its "discard a card" drawback
Amass The return of the amass mechanic from War of the Spark is a massive shock
That said, I don't think he's especially good, even in the context of a ~1.5 card combo, and probably caps out at a low Bracket 4
Who Can Join Everyone is welcome
You may put that card on the bottom.) Land Land (CTRL to add secondary) Protection Kardur, Doomscourge When Kardur enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able