Hades Ex stuff:
The crafting material is a piece of Hades power and it is touching how it tries to invoke a part of him may live on(as in memory form) through it.

Mount is just a whim that Emet-Selch created barely taping into his power to do so.

Suppose we do get to see Lahabrea again in some form, hopefully no more than that he should remain dead like all currently slain ascians.