Just finished my first solo potd run, the build performed slightly worse than I expected, but I decided to post it anyway for some advices to get a better understanding of the game.
Race: Coastal Aumaua (doesn't really matter, I picked it so that I didn't have to worry about stuns)
Class: Trickster/Soul Blade. Trickster for safety, Soul Blade because I wanted something melee.
Skills: Eventually Arcana + Alchemy, History. This build has no sustainability without consumables, and there's no game-breaking synergy for FS content.
Stats (Before Berath's Blessing and other buffs):
MIG 8
CON 9 (I chose Rauatai background for RP, should've put 1 point somewhere else)
DEX 18
PER 18
INT 16
RES 6
I wasn't confident enough to furthur dump CON and RES. I'm pretty happy about high DEX and INT because maintaining cipher buffs was a pain, it would have been more miserable if I went lower. Also I didn't feel the need for MIG as weapons are the primary source of our damage.
Weapon proficiencies: Spear, Club, Sabre, Large Shield, Morning Star
Food: Captain's Banquet. Again a safe choice. Action Speed helps with those buffs and immunities are always nice. Hot Razor Skewers might have been better but with the help of Body Attunement I don't think there was an occasion I seriously regreted my choice.
Pet: Abraham (reduced recovery from armor, heal on kill)
And other no rest buffs
Abilities (rogue): Escape, Crippling Strike, Gouging Strike, Dirty Fighting, Riposte, Adept Evasion, Persistent Distraction, Deep Wounds, Deathblows
I spent most Guile on Escape, Crippling Strike and Illusions spells, and I had no idea how to make invisibility abilities work, so I picked none.
Abilities (cipher): Whisper of Treason, Lingering Echoes, Iron Will, Draining Whip, Hammering Thoughts, Body Attunement, Borrowed Instinct, Disintegration, The Empty Soul.
Most are "fast" spells. I only picked those essential for melee, except Whisper of Treason and Disintegratin are too good for any cipher. Secret Horrors is amazing but Trickster already have Ryngrim's Repulsing Visage. Since it's mostly melee, Rapid casting and Farcasting are unnecessary.
Abilities (general): Two Weapon Style, Weapon and Shield Style, Bear's Fortitude, Snake's Reflex, Bull's Will, Tough, Uncanny Luck, Improved Critical.
Gear:
Weapons: Stalker's Patience, Kahua Hozi (optional), Kapana Taga, Scordeo's Edge, Bronlar's Phalanx, Grave Calling.
Stalker's Patience is our main hand most of the time. Off hand is Kapana Taga later Scordeo's Edge. Grave Calling trivializes vessal combats as all damage from its Chill Fog is considered weapon damage so even if there're non-vessel enemies, we can spam Soul Annihilation on them nonstop.
Head: Blackened Plate Helm. The Maw of Ingimyrk for beast fights in SSS.
Neck: Baubles of the Fin, Charm of Bones
Chest: Blackened Plate Armor / Reckless Brigandine, depending on incoming damage type.
Back: Cape of the Falling Star, The Giftbearer's Cloth
Hands: Bracers of Greater Deflection, Gatecrashers, Burglar's Gloves
Fingers: Entonia Signet Ring, Ring of Minor Protection
Feet: Boots of the Stone, Rakhan Field Boots, Sandals of the Water Lily
Waist: Blunting Belt, The Undying Burden, Girdle of Eoten Constitution
General Strategy:
I have to admit I skipped those lower level combats, even though with charm I imagine they might be doable.
This build starts to work when we get borrowed instinct. Start the combat with dual weapons if enemies are melee heavy or standing closely. Large shield with modal for scattered archers and mages. Mirrored Image / Llengrath's Displaced Image + Borrowed Instinct to start with, if there's space for a little more kiting then add Body Attunement, otherwise Repulsive Visage when surrounded in melee, this should significantly reduce incoming damage and give lots of disengagement hits and free focus, which can be used to SA archers or casters.
Against mass high level archers / mages I had to just buy enough time for Borrowed Instinct then Escape to a relatively safe place for Scrolls of Great Maelstrom.
In most cases combat is all about avoid dying in the first few seconds and find best targets for Borrowed Instinct / Body Attunement.
Specific Encounters:
3/4 Megabosses, SSS crocodile and Oracle of Wael were cheesed by Gouging Strike. This build can't push defensive stats to extreme and lacks healing, so I couldn't find a way to play fair against them. I think the strongest boss I managed to defeat in a straightforward fight was the Dracolich from BoW and it was all about keeping the buffs up, easy and boring.
Hauani was the one I thought I had the strategy for, but didn't quite work out in reality. After Gouging Strike it to near death I couln't reliably get Club modal (lowering will) + Borrowed Instinct + Morning Star modal (lowering fortitude) + Disintegration without getting killed even with full buff, inserting any heal other than Second Wind will cause the debuff on it to expire and retrying takes forever, so I just gave it up.
I guess that's about it. Trickster is always pretty good, but cipher buffs are a little unreliable and certainly become a chore very quickly. To be honest I don't feel pround about this run, just "finally it's over". I hope I could be able to make SSS and FS fights less arcana reliant next time.