Elemental HERO Darkbright

Level 6 DARK/Warrior Fusion Effect
2000 ATK / 1000 DEF

"Elemental HERO Sparkman" + "Elemental HERO Necroshade"
Must be Fusion Summoned and cannot be Special Summoned by other ways. If this card attacks a Defense Position monster, inflict piercing Battle Damage to your opponent. If this card attacks, change it to Defense Position at the end of the Damage Step. If this card is destroyed: Target 1 monster your opponent controls; destroy that target.

Rulings – Yugipedia

Printings:

Tactical Evolution: TAEV-EN042 (Ultimate Rare) - 2007-08-15
Tactical Evolution: TAEV-EN042 (Ultra Rare) - 2007-08-15
Duel Terminal 4: DT04-EN036 (Duel Terminal Normal Parallel Rare) - 2011-01-25
Legendary Collection 2: The Duel Academy Years Mega Pack: LCGX-EN063 (Super Rare) - 2011-10-04
Speed Duel GX: Duel Academy Box: SGX1-ENA25 (Common) - 2022-03-17

Prices:

Cardmarket: 0.34 €
TCGplayer: $ 0.42