Mewtwo & Mew-GX is card #SM191 of 248 in SM Black Star Promos (2017), a Promo illustrated by sui. At about $357 it is the #2 most valuable card in the set. It is one of 89 Mewtwo cards printed so far.
2 copies have been graded by players in Holobrook's grading game. None has come back a 10 yet.
POP 1 is still open for PSA, BGS and CGC: the first player to grade this card a 10 with each company gets a one-of-a-kind POP 1 slab. See the Mint
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 & Mew-GX from SM Black Star Promos sells for about $357. A PSA 10 is worth more, roughly $1,784 by our estimate, and a PSA 9 around $821.
It is a Promo.
sui drew the art for this card.