Ninkondi Prime- Red Rain build is designed for Steel Path.

I use it with [Wisp] as [Wisp] is my best frame. You can reference the [Wisp] Build I use with the link below

Grim Wisper Build

The [Wisp] build above uses Gladiator mods to enhance the critical chance combo and damage, When my life is draining using the 3rd ability helps you [Recover] health and kill quicker

This build primarily builds up a combo, as the combo gets higher you'll see Red Crit rain from your enemies.
I did a video of a Steel Path Defense Mission Solo to show how it works. This is 1 session of 5 waves. Enjoy!

Hope you enjoy the video and have fun with the build.