Where to use Memory Core II?

[Mathis]

I still haven't found where to use this item even after killing the big boss in N'Erud. Does anyone know where should I use the Memory Core II?

[Sir Floyd The Breathless]

Just found it as well, no idea. I've looked for about 3 hours now and no luck. I tried to sneak up on the Custodian because the item description references him, but no luck.

[Sir Floyd The Breathless]

Update: when you enter the Ascension Spire, there is a little alcove on the left with a hole. Drop down the hole, there will be a vendor you can craft and buy supplies at. To the right there is an elevator, go down the elevator and there will be a giant room with an altar containing the missing 2 cores. Insert the core and continue.

[Sir Floyd The Breathless]

There are a couple of secrets in that room, find them yourself.

[Mathis]

Thanks for this! I found the hole in the floor and got the two purple items in there. I also just got the engineer class in this map so I guess I've completed all hidden collectibles in this area.