The Wicked Avatar

Level 10 DARK/Fiend Effect
? ATK / ? DEF

This card cannot be Special Summoned. This card cannot be Normal Summoned or Set except by Tributing 3 monsters. Your opponent cannot activate Spell or Trap Cards until the end of their 2nd turn after this card is Normal Summoned. The ATK and DEF of this card are each 100 points higher than the highest face-up monster's ATK on the field (except "The Wicked Avatar").

Rulings – Yugipedia

Printings:

Shonen Jump Vol. 5, Issue 11 promotional card: JUMP-EN017 (Ultra Rare) - 2007-11-01
Collectible Tins 2010 Wave 2: CT07-EN023 (Super Rare) - 2010-11-02
King's Court: KICO-EN061 (Rare) - 2021-07-08

Prices:

Cardmarket: 0.10 €
TCGplayer: $ 0.23