Mewtwo-EX is card #XY125 of 211 in XY Black Star Promos (2013), a Promo illustrated by Eske Yoshinob. At about $161 it is the #12 most valuable card in the set. It is one of 89 Mewtwo cards printed so far.
1999Base Set
2003Ruby & Sapphire
2006Holon Phantoms
2009Pokémon Rumble
2013Legendary Treasures
2015BREAKthrough
2019Unified Minds
2023Crown Zenith

















See the full XY Black Star Promos card list
An ungraded Mewtwo-EX from XY Black Star Promos sells for about $161. A PSA 10 is worth more, roughly $1,290 by our estimate, and a PSA 9 around $452.
It is a Promo.
Eske Yoshinob drew the art for this card.