Camillo is a Light unit obtainable by clearing the Light selection quest. Depending on which sub job you want to go with him, he can either be a pretty decent mid~long range damage dealer, or a bruiser on the frontline.
Since he's a free unit, shards to reach 120 EX are free, and he can be a pretty decent damage dealer if you want to invest in him. His Dragoon main job has high multiplier attack moves, self 42% ATK buff (Dragons Kin), and 40 defense penetration from passive (Dreadlance Mastery).
Having Sniper as a sub job gives him additional range from passive and self-buff, and comes with some decent debuffing attacks. The combination of 40 defense penetration from his passive + Target gives him 80 defense penetration. This could make him good against meta teams in PvP where a lot of people use a tank and Dark damage dealers like Helena (Black-Robed Witch). Pugilist sub is situationally useful depending on your team.