As Forge Master, it was his responsibility to ensure that new recruits were trained as Techmarines as the Chapter was rebuilt. He had identified Neophyte Narro as having a natural gift for practical problem solving, and had begun his early training shortly before the neophyte's death in the 21st Salvation Team, under Sergeant Tiresias. He also accepted Neophyte Bokari for possible apprenticeship to the Forge after he delivered considerable amounts of power armour recovered from various Tyranid Hive Fleets.
Sebastion had an ongoing project, which was the restoration of damaged or lost Terminator armour. After the fall of Sotha, the Scythes were apparently left with only three such suits, and Sebastion's acquisition of a fourth partial suit was a major leap forwards in putting together a Codex-approved squad.