Mythical Beast Medusa

Level 4 LIGHT/Spellcaster Pendulum Effect
1500 ATK / 1500 DEF

[ Pendulum Effect ]
If you have no card in your other Pendulum Zone: You can target 1 monster in your GY that you can place a Spell Counter on; destroy this card, and if you do, Special Summon that monster, and if you do that, place 1 Spell Counter on it. You can only use this effect of "Mythical Beast Medusa" once per turn.

[ Monster Effect ]

Each time a Spell Card is activated, place 1 Spell Counter on this card when that Spell resolves. Once per turn, during the Battle Phase (Quick Effect): You can remove 2 Spell Counters from your field, then target 1 face-up monster on the field; its ATK/DEF become half its current ATK/DEF until the end of this turn.

Rulings – Yugipedia

Printings:

Extreme Force: EXFO-EN024 (Super Rare) - 2018-02-01
Structure Deck: Order of the Spellcasters: SR08-EN009 (Common) - 2019-04-19

Prices:

Cardmarket: 0.02 €
TCGplayer: $ 0.14