Discovery, Exploration
Now that you know what needs to be done to get to the Phylactery Vault, you just need to clear out enough Thayans in enough zones to make sure they cannot thwart your plans - and find more glyph keys so you have enough to pull it off.
You know what you need to do to get to the Phylactery Vault, but now you have to clear a path.
With your new knowledge to guide you, you return to the Abyssal Gates to finish clearing them, then make your way to the Swine Run sector of the Blood Pens.
You make quick work of a deathlock wight and some skeletons guarding a swine pit and manage to collect three more glyph keys.
You have more than enough keys, you just need to disrupt the right number of Black Gates across the multiple sectors now.