Well if you like casters I think it is fun.
Basically, you should aim to be able to limit weapons use only to powerful area ability (e.g. kitchen stove thunderous report ) or in rare cases while your focus is not auto-recharging
If you manage to put up your summons before being surrounded usually you are able to keep the summons up forever with at least 15 Intelligence /brisk recitation while having your focus auto recharging, IIRC you can reach 4 focus/sec recharging max so e.g. in theory assuming 3 phrases to spam a trobadour her revenge in 9 sec you can perma cast also up to level 3 psion spells, and so on e.g. ancient weapons 32 sec - 8 sec cast up for 24 sec you can use to spam > 90 focus worth cypher spells
Usually summons can make a meat wall to avoid being surrounded in melee, and wand modal can help making ranged fire less dangerous the first seconds until you can use e.g. Secret Horrors/Blind, but anyway with enemy groups you may need to lure enemy with traps to get enough time to put the summons up
(about Hylea challenge, note that you could gain a few seconds with telekinetic burst on Vela but still too random without a bunch of priest scrolls)
It worked well for me so far as pre-ultimate level solo / no rest build (without Hylea challenge/iron man because first one is frustrating without a priest and second one is always frustrating. Also no Eothas, that can be also frustrating but probably it is possible) and I managed to kill a few dragons with it
Race: probably not necessary, but I like pale elf also for fire/ice resistance, perception, high perception is always needed with POTD/upscaled
Might: 13 base+gift of the machine for a nice damage/healing boost
Constitution: 9 base as less is hard especially at the beginning if you want to kill something. Lately you get e.g. + 2 Ngati Blessings, +2 Konstanten boon, +1 Upright Captain Belt (we can aim for no-rest boon as we have infinite resources)
Dexterity: 12 base + 1 elf + 1 e.g. boots of the stone for a nice little action speed boost
Perception: 18 base + 1 elf + 1 white that wends + 1 far effigy Sagani, lately + 1 Konstanten boon, + 1 e.g. horns of the bleak mother
Intellect: 15 base, this is needed to keep summons always up, lately + 1 konstanten boon and other items eventually
Resolve: 8 base (less makes it hard to survive), lately + 1 boots of the stone
Brisk recitation always on.
At start:
modals: medium shield (best survivability) and arquebus (best alpha strike damage/accuracy)
Trobadour: Come Come soft winds of death + try thrice was she wronged... (so you can avoid keeping the skeletons that are not really useful), if it's too hard in the first fights having if their bones... may be easier but you get stuck with them so not ideal
Psion: whispers of treason (survival help at the beginning, always great lately if you have not enough focus for ringleader)
level up:
Trobadour:
thrice was she wronged upgrade is one of the best low level damage spell (area spell + nothing wasted for single target)
thick grew their tongues makes interrumpting enemy easier automatically, ancient memory can save your life when soft winds of death is not enough/in between active combat
Green level 3 phrases wurms are all in all your best ally for most of the game (fast enough to summon to be easily always up, good damage/health), for enemies resistant to fire you may want also the ogres but 3 summons is better than 2 and i usually end high level with only the green wurms and the ancient weapons summons
the long night is nice but not really needed as you can spam secret horrors
the bride caught (quick+ insightful) is great for a spell spammer
the brideman slew + update can be powerful (+5 might +5 constitution + 5 resolve auto renovating on kill) and I had it a couple times absurdly powerful, maybe a glitch managing to kill tons of cannon fodder skeletons with screaming souls, that made it almost infinite time
Eld nary is always great, but especially when your enemy is both resistant to fire and electricity
finally, our aces: called to his bidding, and many lives pass: the sinergy with screaming souls is amazing
Psion: soul shock is a great area spell you can use forever if you keep your summons up. Ideally you should try to spam it after secret horrors -> (lower fortitude) -> blind (lower perception) and get penetrating visions.
Ectopsychic Echo can also be great damage with 3 permasummons it should be easy to place one behind enemy lines if you want
pain link may be necessary to survive/slowly kill a tough boss damaging your eternal summons, at least until you can spam disintegrate and/or screaming soul
psychovampiric shield can help until you have borrowed instinct, and it is always nice
Silent Scream is great to save your hide (stun) and raw damage/gain time with a tough melee enemy
Borrowed Instinct is your best step for easier survivability and bypassing tough defenses and ringleader can make impossible battles against too many enemies at once a possible win
disintegrate is probably the best single boss killer available, before of it you can use soul ignition
get the empty soul ASAP, hammering thoughts is not really necessary for this build as we do not aim to use weapons much ideally but always nice to have
screaming souls: now this is where the real fun is: spam this on your perma ancient weapons or on your Many lives pass skeletons cannon fodder
e.g. something like this
gear: differently from priests ultimate builds, we can not be unkillable so an armor helps, but with Abydon challenge is a resource sink so better to keep and use all the decent armors you find and drop them when they are ruined in this case. Same with medium shields, even low level medium shields help as the modal is great
so e.g. exceptional scale armor (keep the special armors for very hard encounters but be prepared to pay a lot to repair them). if not using Abydon Challenge, there are many good armors (e.g. deltro's cage + 2 electricity, Nomad brigandine, Devil of caroc, miscreant leathers...)
neck: dual necklace of fireballs, dual stone of power, strand of favor, cog of coh...
hands: dual missile gloves (we like dual things for a no rest run)
rings: ring of greater regeneration, ring of focused flame with the necklace, ring of solitary wanderer, chameleon's touch...
[EDIT] weapons: kitchen stove ability is great, as any weapon property lowering enemy defense/offense, rising player defense/offense, not using weapons direct damage you also can avoid a money sink with Abydon challenge. Sasha's Singing scimitar is great, using grave calling to kill the skeletons is not as easy as it seems in practice and probably not worth as you have lots of spells to choose
boots: boots of the stone
belt. upright captain
pet: otto startcat, epsilon, peter, the animancer cat
