Without the bug, it seemed to me that playing a Shadow Monk is not worth it for a Psychic build. But hey, it IS quite flavorful.
I already have a playthrough with the class and loved it, but I want another one with the pure psy theme(including illithid powers).
My impression is that it was a decent damage dealer(compared to other martials) with superb stealth and mobility/verticality - probably the most mobile class in the game. Huge ground movement distance with step of the wind and what amounts to a freecast misty step(no spell slot involved) which also gives you advantage on the next attack. Shadow strike is also a teleport attack. It is the forgotten realms version of X-men's Nightcrawler and very fun to play.
I'm planning this build and gear loadout:
Strenght 10(8+2 vigor potion)
Dexterity 20(17+2 ASI+ 1 ethel's boon)
Constitution 14(13+1 resilient)
Intelligence 10
Wisdom 18(16+2 Shar's mirror)
Charisma 10
Feats ASI, resilient constitution and savage attacker
Gear Loadout:
Head: Diadem of arcane sinergy(adds wisdom modifier to weapon attack damage after inflicing condition, which I will do every single round pretty much)
Body: Robe of Supreme Defences(adds wisdom modifier to all saving throws while concentrating)
Cloak: Deathstalker Mantle
Gloves: Brain Drain Gloves(cumulative wis, int and cha save penalty up to -7 to enemies when inflicting psy damage - this has great synergy with the resonance stone effect on enemies)
Amnulet: Sentient Amulet
Ring 1 : Shadow Blade Ring
Ring 2 : Strange Conduit Ring
Boots: Boots of Unhibited Kushigo(adds wisdom modifier to unarmed attacks)
Resonance stone in the backpack
The basic shadow blade attack would be 2d8 + 1d4(Strange Conduit) + 5(dex modifier) + 4(wis modifier with arcane synergy). All doubled with resonance stone. Shadow strike adds another 3d8(also doubled). All pure psychic damage. There is potential for two shadow strikes in a single round if I proc deathstalker invisibility after the first attack(assuming I start said round hiding or invisible). Also occasionally add flurry of blows to the mix(2x 1d8 + 1d4+ 5 dex modifier + 4 wis modifier). It is respectable damage output.
I might swap braindrain gloves for duellist gloves if hitting things becomes a problem. In that case might have to swap the diadem for other headgear as well. Might swap the amulet to fey semblance occasionally(though githzerai mind barrier and heroes feast already basically cancels out the resonance stone saving throw disavantage malus).
I don't know if using psionic overload for extra 1d4 damage is worth it. It will hardly break concentration, but will situationally break invisibility and stealth.
For fighting against constructs I would swap gear since they are immune to psy damage(staff of the ram probably). Against undead remove the resonance stone since it doesn't affect them.