Talk:Specter (Gear)/@comment-5446802-20140918224637/@comment-65.25.100.112-20140921112446

Vapor - Spawns at the starting level of the enemies in the current mission.

Phase - Spawns at the starting level of the enemies in the current mission, plus 3 levels.

Force - Spawns at the starting level of the enemies in the current mission, plus 5 levels.

Cosmic - Spawns at the starting level of the enemies in the current mission, plus 10 levels.

Basically, they become much harder to kill as you progress through the tiers, I'm not sure if their damage output is increased though.