You know one aegis arcanum spell than normal.
Prerequisites: Aegis arcanum class feature.
Benefit: Each time you take this feat, you gain one additional aegis arcanum spell slot. This spell slot must be of a level equal to or lower than the highest level spell you can cast.
Benefit: Without this feat, you gain only one aegis arcanum spell of a given spell level.
Benefit: You can gain Extra Aegis Arcanum up to three times.