all right, i am going to fully explain all of my findings on summons. from damage scaling to survivability to minmaxing.
first let's go over everything that can increase your your minion damage.
-passive tree minion nodes
-feast of cankers (FOC) unique (2x is necessary if you want to enjoyably do any endgame content)
-fatal pact passive procced by weakness ailment (more on this later)
-a weapon with massive base damage (staff or dagger)
-minion skill level and damage mods (do NOT take attack speed mods, they have little to no effect)
-skills that apply buffs to you and allies (not worth it as a pure summoner)
-the trial unique belt
now lets go over what you will need to be a proper summoner in the current patch
MINION NODES: take em all, damage reduction, health regen, health, damage, attack/cast speed
-regen, health and damage reduction drastically increases your minions survivability which is absolutely necessary due to the health reduction from 2x FOC
UNIQUES: 2x FOC (cheap to buy, join the wolcen trade discord), the trial (very very expensive but a big game changer), genesis (more on this later)
FATAL PACT: there is an interesting interaction between fatal pact and the block based passive notable sacred oath. by stacking a modest amount of block chance you can apply 3-4 stacks of weakness per block which in turn is also applied to you; reaching 10 stacks to proc a 20% damage buff to allies within 5m becomes automatic and often.
CURSE AILMENT: increases enemy damage taken per stack. genesis will release a shadow damage nova that seems to have a high base curse chance whenever an enemy accumulates 5 stacks of weakness ailment, it will also cast bulwark on top of an enemy when they accumulate 5 stacks of curse increasing your and your minions survivability.
WEAPON AND GEAR/SOCKETS: a high primarily shadow damage staff or dagger 3x offensive 3 slots with curse duration jewels. legs and chest should be heavy for block chance, use all defense socket 1 for block chance jewels all other armor use bruiser. rings and ammy whatever works.
only the weapons BASE damage will affect your minions damage, spell damage and attack damage will not affect it nor will any increase to "weapon damage" in your character stats screen.
BUFFS: if you want to do a hybrid caster summoner or make use of buffs use thunderstrike with the mod rebuilding the trinity
SUMMONS: imo 3x parasite and 3x livor mortis is the only way to get anywhere as a pure summoner, the swarm skills are garbage.
-3x livor mortis with generational grief will give you the survivability you need (rend variant is best, spec all other points into damage mods).
-parasite gives you sustain, stronger minions, and a reliable form of curse application against bosses. ONCE YOU HAVE YOUR DESIRED MINIONS DO NOT KILL TRASH MOBS WITH THIS SKILL, if you kill em with it your minion(s) will be replaced.
+most enemies are trash as parasite mobs, here is a list of setups that work ranked SABC etc (keep rerolling mandates to find your summons)
S-3x tormentors : (not frost tormentors, just tormentors) they spam and i mean spam a high damage massive aoe (somewhat rare)
A-9x tainted primordial armor : their ai is a little derpy but the sheer volume of sweep attacks combined with their survivability does work well (common)
C-3x experimental amalgams, spitters, frost tormentors (common)
D-3x wallbreakers (common)
Meme tier- 9x bears (extremely rare)
F- everything else
-setup parasite 1 to steal hp and apply curse (shadow damage convert, ailment chance, minion resist, increased leech), 2 rust drinker and willpower leech, minion resist, 3 minion resist and whatever.
all in all summoner builds scaling is harshly gear and coin reliant
here is my current passive build that makes use of everything stated above, you will need to dump the majority of your points into toughness and the rest into wisdom (try to get around a 30% curse ailment chance) hope this helps.
if you have any findings or skill interactions worth mentioning please share your insights.