kingdra pokemon card - SWSH10: Astral Radiance Trainer Gallery Attack 2 Pokemon Card Game/[S11] Lost Abyss]Kingdra

The answer, I believe, is this

These cards present good alternate win conditions for any monoblack Commander deck, and are extremely functional in a Starscream, Power Hungry deck

While a strong concept in theory, it took until General Tazris release in Oath of the Gatewatch to really bring the Ally deck together in Commander

And they only gave you 11 cards, only one of a rare (and usually something shocking like Clefairy)

If the player can spare two life points, this card is free to cast, and free spells are one of the most powerful effects in Magic

The card is so good right now that Azorius Control even plays three copies(!) in their mainboard