So I won't spoil what the trial is myself but it was spoiled for me due to an NPC so this is a word of warning if you don't want the same to happen to you.

I generally check quality of life stuff first in a new patch and this time I wanted to check to see what the new Doyen's Clan Marks could get me and if I should farm some. So I went to Eschina (Primal Gear Exchange) and in her categories blatantly showed who the boss of the trial was.

I'm a little mad because it denies me my reaction to figuring it out in the story.