Blacephalon (SM221) [Sun & Moon: Black Star Promos] Phyrexian Horror this Character gains [Double Attack]

this Character gains [Double Attack] during this turn

Set Name: One Piece Promotion Cards Card Number: ST06-006 Release Date: TBA Rarity: Common Card Type: Character Cost: 3 Power: 4000 [Activate:Main] You may rest this Character : Give up to 1 of your opponent's Characters -2 cost during this turn

But according to my calculations

Set: Secret Lair Drop Series Type: Legendary Creature — Human Advisor Rarity: Rare Cost: {2}{W}{B} If a creature dying causes a triggered ability of a permanent you control to trigger

Blacephalon (SM221) [Sun & Moon: Black Star Promos] Phyrexian Horror this Character gains [Double Attack]Set: Sun & Moon: Black Star Promos Type: Psychic Rarity: Black Star Promo Retreat cost: Colorless,Colorless