Steam Achievement "The Forsaken Masters"

I'm doing some steam achievement grinding today and have been trying to figure out some information on this one: "The Forsaken Masters"

All I could find was relating back to when Zana was around. Seeing as that's not applicable anymore, does anyone have any suggestions as to how I might go about finding out the requirements to get it?

Thanks in advance

Since Zana is gone, I'm not 100%, but these are the most recent requirements that I know of:

Alva — The Vaal Omnitect
Niko — Aul, the Crystal King
Einhar — Farrul, First of the Plains
Jun — The Syndicate Mastermind
Zana — The Shaper and the Elder