Gravekeeper's Oracle (Ultra Rare)

You can Tribute 3 monsters or 1 Gravekeeper's monster to Tribute Summon (but not Set) this card. When this card is Tribute Summoned: You can activate any of these effects, and resolve in sequence, up to the number of Gravekeeper's monsters Tributed for the Summon.
● This card gains ATK equal to the combined Levels that all monsters Tributed for its Tribute Summon had on the field x 100.
● Destroy all Set monsters your opponent controls.
● All monsters your opponent currently controls lose 2000 ATK and DEF.