The modern concept of doing something "under someone's aegis" means doing something under the protection of a powerful, knowledgeable, or benevolent source. The word aegis is identified with protection by a strong force with its roots in Greek mythology and adopted by the Romans; there are parallels in Norse mythology and in Egyptian mythology as well, where the Greek word aegis is applied by extension.
In psionic circles, however, the Aegis is a character who can summon his best self -- his super ego -- to form an armor to protect himself from evil. It forms as armor so tough that the combatant can waid into the fray as bravely as any hoplite can. An aegis can infuse his best self with ectoplasm to form his suit of armor. The armor needn't be visible, it can be invisible -- as the wearer wishes. But the aegis fights on the front lines as a warrior protected by his armor.
- Ectopic Artisan