[Loki] really only needs his invisibility to survive Steel Path, but the extra survivability mods are here purely for overkill. The duration here is plentiful, efficiency isn't necessary because the only abilities you'll be using are the 2 and 4, the range is okay but you can definitely buff that if you please, and strength is pointless on here. It's just preference. Survivability up the wazoo. Ensnare, melee, refresh invis, repeat.

Weapons of choice:

• Primary: Whatever you want. My build doesn't revolve around any primary so use whatever you please.
• Secondary: [Epitaph]. It's entirely optional but if you want to last longer than an hour in Steel Path survival, I recommend running an [Epitaph] with just status mods on it for applying statuses faster. Just makes your life easier. If you don't have it, you can bring whatever you prefer that has a high status chance, cuz this thing is a stat stick and has no utility or damage outside of that.
• Melee: [Rakta Dark Dagger]. Built for gas damage, and provides free overshields for even more survivability because why not. This thing is the workhorse of the build. You might ask why not run [Brief Respite] instead if all I want is overshields and to that I say, you won't be taking advantage of it often. Might as well buff your workhorse.
• Alternative Melee: [Vitrica]. Instead of grouping and gassing, consider grouping and glassing instead. If you do run this melee however, I recommend replacing Primed Sure Footed for Aero Vantage for that extra air-time. Personally, I run [Aero Vantage] even without the [Vitrica].

You stay invisible forever, ensnare enemies, and melee them to your heart's desire. The gas damage will spread and you'll end them pretty quickly thanks to Condition Overload. Going melee-only can easily carry you through high-level Steel Path, even out-damaging usual meta dps frames in some cases. Once you start feeling like you're not killing them as quickly as you'd like, you start using the [Epitaph] on ensnared enemies to apply more statuses faster, making your life easier.