To the uninitiated, Stratos is one of the key allies of He-Man. We say "key" because he's the only one of the "Masters of the Universe" who can fly on his own power.
Stratos is the leader of the people of Avion - a race of humanoid creatures with bird-like features and abilities - such as the power of flight, aerial acrobatics and enhanced vision.
Stratos enhances his power of flight with a jetpack and adds to his ability to kill anything from the sky with a pair of brass knuckles that fire lasers.
Stratos plays the role of a spy for He-Man's team aside from being an aerial combatant.