The Scotland international joined the Blue & Blacks from Edinburgh ahead of the 2025-26 season, having enjoyed two years at Murrayfield. 

Sebastian came through the ranks of Carmarthen and was part of the Scarlets academy, earning Wales honours at Under-16 and Under-18 level.

However, the 30-year-old also qualified for Scotland through his father and spent time with Ayr and Glasgow Warriors during his formative years.  

He made the move to Edinburgh after making 68 appearances for the Scarlets, and extended his international tally to 10. 

The explosive ball-carrier returns to Wales with an enhanced reputation as a well-rounded tight-head with an abundance of experience.