Ugin, the Ineffable (Stained Glass) [Secret Lair Drop Promos] Onslaught the controller of the permanent

the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step

that source deals double that damage to that player or permanent instead

It contains the totality of Alhammarret's notes

haste Hazoret the Fervent can't attack or block unless you have one or fewer cards in hand

The specimen seems to be broken

Ugin, the Ineffable (Stained Glass) [Secret Lair Drop Promos] Onslaught the controller of the permanentSet: Secret Lair Drop Promos Type: Legendary Planeswalker Ugin Rarity: Rare Cost: {6} Colorless spells you cast cost {2} less to cast. +1: Exile the top card of your library face down and look at it. Create a 2 2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand. 3: Destroy target permanent that's one or more colors.