Thus, the terrible secrets of Arlo are revealed in Warframe. Was he really a savior or was he trying to damn the whole system? Was he a powerful threat, or a victim himself? No spoilers here, I'll just show you how to start the fight against the Zeloid Chief Prelate that ends the season.
How to start the boss fight with Zealoid's Nightwave Prelate Emissary
To start the fight against the Zeloid Chief Prelate, the first thing you need to do is check over the Nightwave button in the browser. If you see active Outbreak Missions, now is the time to fight. Any planet with an active Outbreak Alert will have an active Abandoned Assassination Mission that you can participate in.
This mission gives you a shot at the Zeloid Prelate. To access it, you need a Zealot Derelict code. If you look at your navigation screen, a small counter above the Nightwave button tells you how many Infested Invasions are active and which planets they are on. This icon only appears if there are active Derelicts on the star map.
Go to the planet, then look for the invasion icon on the nodes. You can also click on the Invasions tab in the upper right corner of the screen and select the mission from there.
Like all invasions, you have to complete the mission three times to secure your Battle Balance, which is an abandoned Zealot code. When you have the code, you can access the Abandoned Assassination Mission, complete it, and get your rewards. The Derelict is on a new node, orbiting the planet where the invasions are taking place. You can reference the image above.
So there you have it, now you know how to start the fight against the Zeloid Chief Prelate in Warframe.