How to spawn Nemesis boss?

[tjoe1bkhjtqxm 567]

I've already completed main story and reached level 54, yesterday I've done Warzone (last tenth stage included) but no Nemesis or another huge boss appeared, it was just a regular Siege mission same as all the other 9.

 

Meaning I still haven't achieved "Hunter of Hunters" trophy, the only one I'm missing before the platinum. 

I can just keep repeating Warzone stages until he appears or what? I actually wouldn't like do main campaign another time since I've already completed it two times, but if it's the only solution, I'll do it.. 

 

Thanks

[tjoe1bkhjtqxm 567]

Nemesis is not more available, need to hunt down bosses in the Void Crusade after patch 2.0 (I opened the topic):

 

https://neocoregames.com/en/community/hub/ps4-hunter-of-hunters-trophy-kill-5-boss-creatures