Crosis, the Purger [Invasion] Karsus You can only use this

You can only use this effect of "Ascension Sky Dragon" once per turn

you cannot Normal Summon this monster

you can also send 1 Fusion Monster from your Extra Deck to the GY that lists "Fallen of Albaz" as material

Set: Tactical Evolution Card type: Gemini Monster Rarity: Rare Attack: 2350 Defense: 1000 This card is treated as a Normal Monster while face-up on the field or in the Graveyard

incredible

Crosis, the Purger [Invasion] Karsus You can only use thisSet: Invasion Type: Legendary Creature Dragon Rarity: Rare Cost: {3}{U}{B}{R} Flying Whenever Crosis, the Purger deals combat damage to a player, you may pay {2}{B}. If you do, choose a color, then that player reveals their hand and discards all cards of that color.