The Mega Sableye & Tyranitar GX (226 / 236) card can be found in the Unified Minds set.
Recently sold 21 times and based on those sales is worth around £51.68.
Currently, there are 4 open listings for this card on ebay.
This card sells in the range of £34.55 to £68.81, making it quite volatile.
This Rare Ultra card was illustrated by chibi.
The fact that it is a GX card makes it one of the more valuable cards.