Davan Shakari had the same superhuman advantages of any member of the Shi'ar. These powers would include enhanced strength, enhanced agility, and hollow bones.
To increase the powers listed above he wore a costume that augmented his strength to higher superhuman levels. This also enabled him to control minds to a limited degree. The suit also enabled him fire concussive force blasts from his hands. He had many other advantages and was comprised of alien technology several centuries more advanced than that found on Earth.
Although Davan first appeared in X-men 97, The costume and name where used as early as in Uncanny X-Men #51 and 52. Cyclops used this disguise to enter Mesmero's Headquarters and attack the evil mutants led by Magneto. How Cyclops got the costume and if it has any relation to Davan has never been explained.
Magneto also used the costume when he put Gambit on trial for his part in creating the Marauders for Sinister.