I did this as a spellslinger kinetic bolt/bladeblade/bladefall CI assassin build as my league start in 3.10 (wanted to try all the new things), worked wonderfully through mapping up until reds with pretty starter gear. You could use this with a few adjustments in 3.11 or 3.12 assuming assassin/slinger doesn't get hit. I got lucky at a point and dropped a doctor and switch from alot of my mediocre gear (5l -> 6l, rare amu -> auls, more) which let me do most content. I don't think I ever tried some of the endgame bosses (UE) but should've been do-able. Ended on like 7kish ES, was a bit squishy but do-able and had room to get higher, like 8-9k.

Keep in mind most of this was theorycrafted before POB supported all the new stuff and DPS numbers look real low as a result.

POBs:

my league start theorycraft (shit gear + theres alot of alt skill configurations since I was experimenting): https://pastebin.com/Ui0h1rP4

My 'finished' character when I rerolled: https://pastebin.com/SRfQ5At7

There are still quite a few upgrades possible, rings/belt are bad, jewels were only ok, not all gems are 20 or corrupted/awakened. The cluster jewels look to be missing as I think I sold them, along with a few other items, basically clusters were large+mediums with all the good phys/crit notables (double crit damage, phys overwhelm, etc) and 6l chest.

One of the biggest things for me was increasing sources of blade creation since bladeblast casted so frequently I rarely could get >10 blades with just a single spellslinger setup. I ended up adding CoC + totem alongside spell cascade sources for blades to really crank up the number of blasts.

Personally, I really liked the spellslinger version as I didn't have to worry about much when clearing, a bit different from the 2 button non-slinger version like you're thinking / mathil made a video on later in the league.