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
The Heavens mystery already gives you most of the spells that work with Awesome Display: color spray, hypnotic pattern, and rainbow pattern. About the only one you're missing is Scintillating Pattern.
If you want Scintillating pattern, the only good way I know of to get it as an Oracle spell is to be an Elf for the oracle archetype Ancient Lorekeeper, at which point you can select it as your level 9 bonus spell (instead of its usual level 8 spell status)
However, that hurts your charisma due to a lack of a CHA race bonus, which is the last thing you want to do with this build, so consider asking your GM if a Half-Elf would qualify for that archetype due to elf blood. If so, that's probably the way to go if you want Scintillating pattern. At a level 9 spell, that's pretty late to plan for though...
Aside from that, boost your charisma like mad of course. +6 Headband, inherent bonus from tome, and so on.
If you have 2-3 spare feats, something any character can do to make your spells harder to save against is getting Nature's Soul and Animal Ally (Boon companion optional) and building the animal companion as a Dazzling Display build to apply Shaken to the enemies for -2 to their saves.
Lastly, get the Seeker oracle archetype. Among other perks (Trapfinding) you get +4 to overcome spell resistance with your bonus spells (i.e. all your pattern spells)