Fabled Ashenveil

Level 4 LIGHT/Fiend Effect Monster
1600 ATK / 1200 DEF

If this card attacks or is attacked, during damage calculation (in either player's turn): You can send 1 card from your hand to the Graveyard once per battle; this card gains 600 ATK during that damage calculation only.

Rulings – Yugipedia

Printings:

Duel Terminal 3: DT03-EN065 (Duel Terminal Super Parallel Rare) - 2010-09-25
Hidden Arsenal 3: HA03-EN037 (Secret Rare) - 2010-12-02
Battle Pack: Epic Dawn: BP01-EN158 (Common) - 2012-05-24
Battle Pack: Epic Dawn: BP01-EN158 (Starfoil Rare) - 2012-05-24
Battle Pack 3: Monster League: BP03-EN079 (Common) - 2014-07-31
Battle Pack 3: Monster League: BP03-EN079 (Shatterfoil Rare) - 2014-07-31
2-Player Starter Deck: Yuya & Declan: YS15-END07 (Common) - 2015-05-28
Dark Legion Starter Deck: YS15-ENL09 (Common) - 2015-05-29
Hidden Arsenal: Chapter 1: HAC1-EN134 (Common) - 2022-02-24
Hidden Arsenal: Chapter 1: HAC1-EN134 (Duel Terminal Normal Parallel Rare) - 2022-02-24

Prices:

Cardmarket: 0.05 €
TCGplayer: $ 0.10