Sentinel is a kind spark, wanting what's best for Cybertron. He always had aspirations to be more than a miner, more than a cogless mech, more than what society had forced him to be. His clostest friend - Arachnid - was very protective of him, keeping him out of trouble as best as she could. The two were basically inseparable. They both looked up to Orion and Diaxus Prime, respecting them deeply just as everyone else did. Sentinel always put others before himself, no matter the shape he was in.