B.E.S. Crystal Core

Level 5 WATER/Machine Effect
2100 ATK / 1000 DEF

When this card is Normal Summoned, put 3 counters on it. This card cannot be destroyed by battle. If this card attacks or is attacked, remove 1 counter from this card at the end of the Damage Step. If you cannot, destroy it. Once per turn, during your Main Phase, you can change 1 face-up Attack Position monster your opponent controls to face-up Defense Position.

Rulings – Yugipedia

Printings:

Cybernetic Revolution: CRV-EN021 (Super Rare) - 2005-08-17
Cybernetic Revolution: CRV-EN021 (Ultimate Rare) - 2005-08-17
Champion Pack: Game Three: CP03-EN015 (Common) - 2007-05-15
Dark Revelation Volume 4: DR04-EN021 (Super Rare) - 2007-11-14

Prices:

Cardmarket: 0.53 €
TCGplayer: $ 0.56