Lost in quest line for unlocking Zereth Mortis

would yall please let me know if I need to finish Bastion before Zereth Mortis starting quest will be available to me. there is no intro quest giver in Oribos for me right now.

You meed to have selected a covenant to access the end game chains that are needed to unlock ZM. That means either completing the whole leveling campaign or using Threads of Fate if it’s available to you.

To be eligible for threads you need to have already completed the campaign on another character and be at least level 60. Roh-Tahl on the eastern platform will have a dialog option for it. If he doesn’t and you qualify, congrats, your character is bugged. I’ve seen someone say they got the option to appear using party sync with a low level character, but barring that, you’ll need to complete the campaign.