Is Aegis a Manifesting psionic creature?

Question

Is Aegis a Manifesting psionic creature? And so, can he use Psionic powers? From Ultimate Psionics I believe the answer is "no" but I'm not completely sure. Is there a "feat" or other way that allows Aegis to use Psionic Powers?

Answer 1

An aegis has power points (making them a psionic creature), and no class-specific way to learn to manifest powers (so they aren't a manifester). However, the aegis can cheat a little bit.

The Power Stone Repository customization and the Harness Power Stone customization line that follows it (Improved, Greater, and Superior Harness Power Stone included) allow the aegis to spend power points to use powers from a power stone (basically a psionic scroll) as if they knew the powers. This isn't true manifesting that qualifies you for prerequisites, but that distinction doesn't matter as much as it seems. Some feats that are useful when you manifest a power (such as Overchannel) don't have a prerequisite that calls for a true manifester level.

Plus, the Unlocked Talent feat and Access Psionic Talent feat give any psionic creature that can meet the prerequisites the ability to use a 1st-level power and five 0-level psionic talents (the psionic equivalent to a cantrip), respectively. Unlocked Talent manifesting doesn't count for prerequisites (the Special line has a lot of restrictions similar to the Harness Power Stone customization), but Access Psionic Talent does, even if you aren't paying a power point cost to use the powers.

Of note: A sidebar in Psionics Expanded: Advanced Psionics Guide notes that Unlocked Talent can be gained in place of Wild Talent, in the right kind of campaign. Since an elan gains Wild Talent by default, they'd gain the Unlocked Talent feat instead, so they could manifest a chosen 1st-level power a number of times per day.

HIGH PSIONICS GAMES
In campaigns where psionics is more commonplace, such as the Third Dawn Campaign Setting, it is recommended to remove the prerequisite of Wild Talent from Unlocked Talent and substitute the Unlocked Talent feat for Wild Talent to represent how the ability to manifest powers is common within the world.

Answer 2

The aegis is a psionic class, and someone who has levels in aegis is a psionic creature, that is, has the psionic subtype. From the definition of the psionic subtype,

a creature with the psionic subtype either has a power point reserve or has psi-like abilities,

and the aegis does have a power point reserve.

The aegis cannot manifest psionic powers, however; not every psionic creature can. Instead of psionic powers, the aegis uses power points to fuel certain customizations that utilize them. Also, though the astral suit and its customizations are supernatural according to the rules, and use the rules for supernatural abilities, they are intended to have a psionic flavor. Note that form astral suit says that it is suppressed in areas where psionics are suppressed, like a null psionics field. This isn’t actually special—antimagic field and null psionics field are almost identical in every way, and both of them affect all kinds of magic and psionics equally—but by explicitly calling it out, the authors emphasize that this particular supernatural ability is more of a psionic ability than a magical one.