My [Ripkas] build for Endo farm Sedna Arena. It make use of its unique mod "[Amalgam Ripkas True Steel]" that provide 100% gore chance. You can find more information about gore chance down here
This will give u a chance to get more endo per match, but lower your dps. So make sure to use it when u can finish the mission fast enough

https://warframe.fandom.com/wiki/Amalgam_Ripkas_True_Steel

In short, it will cut more body part for [Nekros] to desecrate that mean even more loot.

Ideally, you wanna use a riven since its disposition is very high.

You want to have riven that can save you more slot for example +range, +damage to grineer, +critical damage and atk speed
+critical chance and +melee damage is not good because Condition overlord will always provide more damage and [Blood Rush] with [True Steel] give you already more critical chance

I use this Ripkas on my khora and nekros. You can find the build for Endo farming on sedna arena (vodyanoi) team here
Khora build: https://overframe.gg/build/64978/
Nekros build: https://overframe.gg/build/64980/
Nidus build: https://overframe.gg/build/64982/