The First Monarch Secret Rare - Legacy of the Valiant Unlimited

Special Summon this card as an Effect Monster (Fiend-Type/DARK/Level 6/ATK 1000/DEF 2400). (This card is also still a Trap Card.) If Summoned this way: You can discard 1 card, then declare 1 Attribute; this card becomes that Attribute, and can be treated as 2 Tributes for the Tribute Summon of a monster with the same Attribute as this card. While this card is treated as a monster, you cannot Special Summon monsters, except monsters with this card’s Attribute.