Unkillable Melee [Nidus].

Step 1 : replace Parasitic Link or Ravenous with Gloom (Parasitic Link may be more useful in survivals).
Step 2 : use Mazinger-Z's Sepfahn https://overframe.gg/build/231867/
Step 3 : use Mazinger-Z's Melee Panzer : https://overframe.gg/build/238211/
Step 4 : use Mazinger-Z's Kuva Nukor : https://overframe.gg/build/242492/
Step 5 : use Mazinger-Z's Daikyu : https://overframe.gg/build/243306/
Step 6 : ???
Step 7 : enjoy endless survivals.

You thought the Unkillable Inaros Melee build was already stupid enough ? Well, try this one.

About this build :

• The whole build is designed to take full profit from Gloom and to provide the best survivability. Enemies trapped in the Gloom area of effect will play their animations at 5% speed (capped at 95% slow-down).
• The goal is to obtain your 100 mutation stacks as fast as possible. To do so, trap large groups of enemies in Larva and spam Virulence on them. Once you manage to get 100 stacks, you are basically unkillable. Acolytes can't kill you and being immune for 5 seconds is enough to kill any remaining acolyte protestor.
• Martyr Symbiosis and Panzer Devolution are additional safeguards.
• Hit & run strategy : you have to run as quickly as possible, hit you enemy and move to the next target. Rinse and repeat.
• If you are using the [Sepfahn] build mentioned above, enemies will die from a very strong bleed effect. You absolutely do not have to hit them until they die from direct damages. You can use a Nukor to speed-up things but this is pretty much unnecessary except for cleaning the place a bit faster.

Notes :

• Arcane Energize can be replaced with anything else : Arcane [Guardian], Arcane Trickery (since this [Sepfahn] build easily performs finishers), Arcane Healing or Nullifier... Your choice. Energize only gives more comfort, Hunter Adrenaline remains the main source of energy.
• I strongly recommend keeping Arcane Strike as it is part of the whole set.