Will a Blitz still 1 hit kill a trojan in Fsc with the fallen set?
Fallen Set w/ Blitz
In short, no. Even wearing one piece of fallen in a 4-man means you can't ohko a trojan
I believe you can OHKO Trojans with one piece Fallen, provided no shots miss. I have a Blitz with Fiend Med and have carried it with full Fallen, and have OHKO'd Trojans with it, if I remember correctly. But all shots must hit.
Plague can OHKO Trojans with 1 piece of Fallen, provided you poison early. I do not know about having full Fallen on Blitz though.
Why mix asi with an autogun that won't benefit from it as much anyway? Much as pure damage is nice and all, plague/volcanic pepperbox would have more appreciation for asi than blitz.
Anyway, if all bullets hit, a single piece of fallen won't hold you back from ocko on Trojan, but the full set just kills your ability to ocko on Trojans.
Definitely not in a 4 man party with a full set. Might still get the chance with just one piece and soloing.
Fallen overall isn't a good option. Shadow defense but fiend penalty.....
At the very least if you still want the "global" medium ASI you could mix vog with one of the gunslinger armors.
You won't have the same fire and shadow resist, but you should be fine. The games values offensive over defense.