4x Extra toxic DMG shard are most optimal
1x [Ember] shard for cast is nice but not necessary

Nourish over one fix energy problem while giving your scuttlers and weapon viral damage

[Archon Continuity] gives corrosive damage on toxic from 4th (which we're on anyway)

Best to use with [Kuva Sobek] for chain reaction (as long as enemies die in 15m proximity, acid shell mod will proc itself)

Efficiency is not needed because if nourish

Range of 79 is more than enough for sling range and gives a little coverage for 2nd skill

Duration to make good uptime of 1, 2, scuttlers and less energy drain on silken

As much strength as possible to boost both nourish damage and silken stride

3rd skill when out of range makes dart just fly in same direction, which can be uses on purpose to stack statuses on one target

With current setup 4 and 1 gets absurdal amount of additional damage, more so if you wall latch, scuttlers deal insane damage by it's own, proc nourish explosion if hit and help with armour strip because if [Archon Continuity]

Arcanes crepuscular for str and crit DMG and molt augmented for even more str

Don't forget to proc invisibility first before using 1 and 4 because if arcane crepuscular additional damage

(Edit: arcane bellicose is better than molt augmented, because with current setup you get enough hp to get full 72% str as long as you're in silken stride, while also boosting it by full 72% value)