Here is Covert Ash!

Secondary weapon: https://overframe.gg/build/109098/
Melee weapon: https://overframe.gg/build/109096/
Companion: https://overframe.gg/build/109100/

Only the above are necessary, you can use whatever utility primary and companion weapon you want.

This playstyle is very specific. To use this setup properly, you must keep Smoke Screen and Silence up almost constantly. While this is happening, you build up your combo counter on enemies with the [Sepfahn] Zaw getting in as many finisher kills as possible. You can continue like this for a very long time, but if there is an unnecessarily high armored enemy, strip it's armor with Shuriken then use your [Sepfahn]'s heavy attack (As long as it's combo counter is all the way up). The damage numbers will blow your mind. Also be sure to use your [Kuva Nukor] every once in a short while, it really helps.

[Ash], the stealth warframe, even stealthier, even deadlier.

Have fun with this!