Duration for Astral Sword psionic power?

[Varyon]

I don't have the relevant book to check exactly how that one is built, but in general, I believe melee Innate Attacks simply exist when you use them and don't when you aren't using them - that is, they can essentially be turned on and off as you use it, rather than needing a moment. Compare to ranged Innate Attacks - you simply shoot eye beams or whatever the round you use them, and aside from that they don't exist. "Attacks – notably Affliction (p. 35), Binding (p. 40), and Innate Attack (p. 61) – are only “on” while you are attacking. An advantage like this requires a one-second Attack maneuver to use; you cannot switch it on continuously without a special enhancement" (B34). The Melee Attack Limitation doesn't say anything to contradict this, although the "only "on" while you are attacking" bit doesn't quite follow considering such can, by default, be used to Parry.

While it may not quite be RAW, it may be more appropriate to have melee Innate Attacks and similar be treated as Switchable, requiring a Ready to turn on or off (in this case, summoning and dismissing your Astral Sword). Note this would simply be a part of the Melee Weapon Limitation, and you don't need to pay for Switchable +10%. To make such be able to be summoned and dismissed as a free action, add a +10% Enhancement (this is based on Hidden +20% from "Natural Weapons," Pyramid #3/65; that's basically the Switchable Enhancement but a free action rather than calling for a Ready to turn on and off). I'd personally let you pay +5% for something that takes a Ready to activate but can be deactivated as a Free Action (for something like an Astral Sword, this is probably a case of being able to drop it, and it disappearing when you do).