A easy-to-obtain power build, geared for gas damage for this to be an all-around versatile weapon for farming missions in late-game. Feel free to use and share this build yourself!
All mods are fairly easy to obtain, but here are some that can be troublesome or easily missed:
"[Heavy Caliber]" probably being the hardest due to the Orokin Vault's rng.
"[Malignant Force]" is fairly easy to obtain from "Corrupted Vor" farming in the void with a 25% drop chance, he drops it as 1 of 4 toxic mods, guaranteed.
"Vigilante Armaments" obtainable through Cetus Bounties is the easiest way of obtaining it. 20-40 range is where it will be. Also may drop from Plains Commander with about a 38% drop chance. Which he is 1 of 3 targets from assassination bounties.