Looking at this handbook (2010), (Be advised that he uses an unusual colour scheme, for people used to modern handbooks.) we can see some general patterns:
At the end of the day, you'll be looking for ways to bypass it. The two power that you should have, therefore, are Crystal Shard and Amethyst Burst. Nice, low-level powers that can be augmented well. Crystal Shard is a ranged touch attack (with all the ways that that can be cheesed). And Amethyst Burst is nice as an AoE.
The general pattern is: find the no-save, no-sr powers that are most compatible with your party, and take... them. Use the rest of your powers on doing Cool Stuff. Have your signature no-save, no-sr (probably ranged touch, though telekinetic thrust, with the right optimization can be cute), and have your backup no-sr, no-attack. In high epic, the game is silly. You should be focusing on "dirty tricks." Either doing the scry & die game with the opposition, or preventing insta-death teleports from happening to you.
You may want to focus on appropriate astral constructs. It's one of your signatures, and summoned monsters, when appropriately optimized, can be incredibly useful. Consider specializing in it with an appropriate PrC.
If you're really playing silly buggers, embrace taint (and the necessary hooks to ignore it), and grab Subverted Psion. That, combined with Thrallherd means that your evil army (all armed with appropriate magical devices of no-save no-sr powers), can just kinda swarm the badguys.
Pay especial attention here, where the optimizer breaks down some of the better choices:
Ranged Attack Roll
Any power you select should preferably be a ranged touch attack. This means rays and the like. In this category, three powers stand out: Crystal Shard (Psion 1), Entangling Ectoplasm (Psion 1), and Crystalstorm (Psion 2). What makes these powers superb choices is that they all fill two other roles: they don’t allow a save (note that Crystalstorm does allow a save against its secondary Con damage effect, but not against its primary HP damage effect), all are instantaneous creation effects and are thus effective in Anti Magic/Null Psionics fields. Finally, none of them are subject to SR/PR.
Ranged attack roll: Crystalstorm (Psion 2), Disintegrate, Psionic (Psion 6)
Melee attack roll: Astral Construct (Shaper 1)
Targets Fortitude Save: Disintegrate, Psionic (Psion 6), Energy Wall (Psion 3)
Targets Reflex Save: Energy Wall (Psion 3), Amethyst Burst (Psion 2)
Targets Will Save: Time Hop (Psion 3)
Allows no Save: Crystalstorm (Psion 2)*
Not Subject to Spell Resistance or Power Resistance (SR/PR): Crystalstorm (Psion 2), Energy Wall (Psion 3), Amethyst Burst (Psion 2)
Area of Effect (particularly for fighting Swarms): Energy Wall (Psion 3), Astral Construct (Shaper 1)**, Amethyst Burst (Psion 2)
Force Effect (for fighting Incorporeal/Ethereal creatures): Amethyst Burst (Psion 2), Astral Construct (Shaper 1)**
Effective against Anti Magic Field/Null Psionics Field: Crystalstorm (Psion 2), Amethyst Burst (Psion 2)
Effective against Globe of Invulnerability: Disintegrate, Psionic (Psion 6)
Creating epic psi powers causes sanity loss, but given that they work like normal peic powers, look around for an epic spellcasting guide and plagiarize. Considering that you'll certainly have thrallherd and/or appropriate leadership chains, you'll have plenty of assistance.
Beyond this, given that you're in a stupid-optimization game, consider:
There are a number of infinite action tricks there. I am especially amused by the save state trick. I would also ask to become a erudite with spell to power. Cause why limit yourself to only psionic tricks?
Best Answer
Honestly, I see that you're trying to be two things, and this might be a bit of splitting point on your build, so I have what I hope is a good and sensible option.
Continue being split over two objective, but do it smarter
You use reformation to Psionic Body, Additional Traits, Power Penetration, Great Power Penetration, Spell Penetration (Mythic), and Persist Power for Psicrystal Affinity, Psicrystal Containment, Burrowing Power, Delay Power, Enlarge Power, and Extend Power. Additionally you reformation away all your offensive powers that allow Power/Spell Resistance away for alternatives that don't allow this defense.
This will let you start fights with a Extended Astral Construct, and let you manifest your blasting power in a more versatile way. While it does lower your options of powers to use, you can use your good selection of Metapsionic feats to make powers fit the situation, and you can apply two of them if you need to, as your glowing rock buddy can hold some of your psionic focus for you.