Mewtwo-GX is card #SM196 of 248 in SM Black Star Promos (2017), a Promo illustrated by MPC Film. At about $19.16 it is the #79 most valuable card in the set. It is one of 89 Mewtwo cards printed so far.
1999Base Set
2003Ruby & Sapphire
2006Holon Phantoms
2009Pokémon Rumble
2015BREAKthrough
2017Shining Legends
2019Unified Minds
2023Crown Zenith

















See the full SM Black Star Promos card list
An ungraded Mewtwo-GX from SM Black Star Promos sells for about $19.16. A PSA 10 is worth more, roughly $95.80 by our estimate, and a PSA 9 around $44.07.
It is a Promo.
MPC Film drew the art for this card.