Number 1: Numeron Gate Ekam - Unofficial YGO Card Search

Number 1: Numeron Gate Ekam 10

Level 1 LIGHT/Machine Xyz Effect
1000 ATK / 100 DEF

3 Level 1 monsters
Cannot be destroyed by battle. At the end of the Damage Step, if this card battled an opponent's monster: You can detach 1 material from this card; double the ATK of all "Numeron" monsters you currently control, until the end of this turn.

Rulings – Yugipedia

Printings:

Battles of Legend: Armageddon: BLAR-EN022 (Ultra Rare) - 2020-07-23
Maximum Gold: El Dorado: MGED-EN083 (Rare) - 2021-11-18

Prices:

Cardmarket: 0.21 €
TCGplayer: $ 0.24