Attribute Mastery

Card type	Monster
Attribute	SPELL"SPELL" is not in the list (DARK, DIVINE, EARTH, FIRE, LIGHT, WATER, WIND, ?, ???, THUNDER, ...) of allowed values for the "Attribute" property.
When you activate this card, declare 1 Attribute. If the equipped monster battles a monster of the declared Attribute, destroy that monster before damage calculation.

In other media

Page	Medium	Debut date
Attribute Mastery (anime)	Anime	2008-02-13
Attribute Mastery (Duel Links)	Yu-Gi-Oh! Duel Links