just personal experience

i've tried every combination between slots 2 and 4 cosmics, his own uniques ,skrull military uniform and a fist of apocalypse artifact whilst doing my brain numbing repetitive tasks

skrull military uniform is good til you can get a really good cosmic but i dont see how it'd replace a good cosmic since blade doesn't really care about power duration, he doesnt have a buff/debuff window that he wants to extend as much as possible

this, overall provided the best outcomes for me. In danger rooms when i swapped from cosmic gear my non signature damage was way worse and it sucked for when i needed my damage without my signature to count (like the brood dr, kurse terminal and so on) I consistently hit around 18.5-20 million range with max stacks on my sig (as a whole)

is a busted ass item, lots of dmg rating, crit dmg and brut dmg. Straight up immortality and it can be chained with med shield (med shield into item proc into med shield). You can kill patrol bosses during the chain invuln and just not care about them at all i wouldn't swap it for anything, 1 death is worse than going in without any artifacts due to the dps drop not dying is the biggest priority

is perfectly fine but will be slower for certain scenarios as you have to build up the stats as opposed to just jump and sig. It might even have better ttk vs a dummy (i didnt test) but in game you kill things by sig count (boss dies in 1 sig, 2 sigs, 3 sigs etc.) so it's kind of irrelevant

Insignia, i just went with whatever % had the highest cd/bd combo in my stash, i like all the attack speed though it helps keeping buffs consistently

blade's easy to play theres not a lot goin on with him

->->->-> then just repeat this while holding and spamming   off cooldown to reduce sig cooldown, pop  at 10 starve stacks then go sig again everything should be dead, if there are enough people boss will be dead after the first rotation, if thats the case might as well use the serum right at the start even at 0 stacks for the small buff

I wanted to post this mainly for newer players, blade is cool and strong so a lot of newer players want to pick him up but dont really understand what to do beyond throwing signature

lv70 legendary 

slot 1: or his own slot 1 unique (the gun not the toxin gauntlets)

slot 2: his own unique or other cosmics with the correct cosmic affix + crit dmg and brut dmg

slot 4 : 

slot 5:

artifacts: anything with any combination of strength,fighting, crit dmg, brut dmg, dmg rating really

if you're a new player please know that cosmic artifacts are just extra and not the core of any builds, just use what you have til you have a replacement