This guide will let you know how to unlock and complete the Nightmare Mode Missions in Warframe. You have to follow the step-by-step instructions to do so.
To unlock nightmare mode, you will need to complete all nodes in a planet.
Once you do, you will see nightmare mode missions in that said planet with different modes/challenges.
A planet that hasn’t been fully unlocked may look like this with Blinking blue nodes or even locked mission nodes. You also need to unlock the junctions.
To Easily Find Nightmare mode missions, you have to go to Alerts.
After completing nightmare mode, the mission will reward you with nightmare mods for weapons, warframe, or companion.