Riven Mod help

[(PSN)k985720419]

Got my first riven mod at the end of the war within. 30+ exterminate w/ no detection and a hobbled dragon key equipped. I figured that I could do oxomoco. 30+, no alarms, since corrupted don't use them. Didn't work. Can't figure out how to kill approx. 150 enemies in stealth essentially without a single one noticing me killing someone else. All at a fraction of my normal speed. Any suggestions?

[FilthyStatusPT]

Grineer Exterminate are quite easy. I have that challenge mylsef and still haven't completed it. Tho, i'll try to see if i manage to do it. For tips, just take a fast melee, with good damage and a loki/ ash / ivara ( tho with ivara that mission is way to easy) and you're good. 

[ThePredicament]

No detection means not being seen at all, not alarms. Try a careful playthrough with an invisible build loki, a quiet gun or aug mod. It's surprisingly pretty hard to do, only one I had to do a few times (even had the sentient no damage one).

[Barely_Ironic]

You have to equip the Riven mod to any rifle, and then take it into the mission for the challenge to be accessible