My [Nekros] set up for Endo farm sedna arena. The core mod should be [Despoil], [Vitality] and [Overextended] (47.5m Desecrate range should be more than enough).

Every other mod is optional. I run those for my maximum QoL.

[Primed Sure Footed] (or [Handspring]) to never stagger or knock down
[Rolling Guard] for remove any harmful status effect or for emergency moment
[Health Conversion] and [Adaptation] make [Nekros] more tanky
[Thief's Wit] to help you dont miss any precious endo that appear nicely on radar.

Aura is preference, [Corrosive Projection] help on high armor enemy on steel path

[Ripkas] would be the preferred weapon for the this farm because its unique mod amalgam Ripkas True Steel
My Ripkas build: https://overframe.gg/build/64984/

Best team composition for endo farm is Khora, Nidus, Nekros, Nekros
My Khora build : https://overframe.gg/build/64978/
My Nidus build: https://overframe.gg/build/64982/
My Nekros build: https://overframe.gg/build/64980/

Optional helminth: Larva (to replace a [Nidus], in that case, you will need maximum range. Replace [Adaptation] and [Health Conversion] for [Stretch] + Augur [Stretch]). Greedy (pull) over [Adaptation], (Decoy) to hold the door, Spellbind to replace [Primed Sure Footed]