Galaxy Knight

Level 8 LIGHT/Warrior Effect Monster
2800 ATK / 2600 DEF

If you control a "Photon" or "Galaxy" monster, you can Normal Summon this card without Tributing. If Summoned this way: Target 1 "Galaxy-Eyes Photon Dragon" in your GY (if possible); regardless, this card loses 1000 ATK, and if it does, Special Summon that target (if any) in Defense Position. This ATK decrease lasts until the end of this turn.

Rulings – Yugipedia

Printings:

Zexal Collection Tin: ZTIN-EN012 (Ultra Rare) - 2013-03-07
Legendary Duelists: White Dragon Abyss: LED3-EN040 (Super Rare) - 2018-09-27
Legendary Duelists: Season 2: LDS2-EN049 (Ultra Rare) - 2021-01-21

Prices:

Cardmarket: 0.09 €
TCGplayer: $ 0.23