Still the Warrior of Light in 6.x and beyond? [Spoilers through ShB]

[Cleretic]

If the unsundered Ascians were able to restore the soul and memories of sundered Convocation members by using their soul crystals, then Venat - if withdrawn from Hydaelyn - may be able to restore Azem using his/her crystal which we have in our possession.

That crystal isn't a soul crystal like the rest, and contains no memories of Azem. It instead includes one of Azem's spells. So it's less like a job crystal and more like a Eurekan memory or Lost Skill from Bozja.

[Vflower]

That crystal isn't a soul crystal like the rest, and contains no memories of Azem. It instead includes one of Azem's spells. So it's less like a job crystal and more like a Eurekan memory or Lost Skill from Bozja.

Is there a line in the game that states that clearly?
When you find Azem's stone, Hythlodaeus explains:

As you will have gathered, each crystal bears an account of the life of a member of the Convocation as remembered by the unsundered.
Lest you worry, they aren't concepts; they are far too incomplete to be so. But they suffice for imbuing memories within sundered souls, that they might be restored to their office. [...]
Defectors having been deemed unworthy of commemoration, no crystal exists for the individual in question.
Or shouldn't exist, at any rate─and wouldn't, had a friend not created one in secret.
A crystal bearing the forgotten name of her office, along with a magick of her own conceiving─a singular incantation embodying her spirit.

So yes, the stone does contain Azem's title and his/her spell, but is that all it contains?
The English version is - as usual, unfortunately - fairly vague on this, but in other languages he says that "Azem's legacy" was stored in the crystal.

When you use your crystal in the fight with Elidibus, you hear lines likely recorded on it by Emet-Selch:

Herein I commit the chronicle of the traveler. Shepherd to the stars in the dark.
Though the world be sundered and our souls set adrift, where you walk, my dearest friend, fate shall surely follow.
For yours is the Fourteenth seat - the Seat of Azem.

"Commit the chronicle of the traveler" sounds like the stone does contain memories of some kind.

With G'raha we were successfully able to fuse the soul and memories of an 8-shard person into a less dense soul. If our stone does contain the legacy of an unsundered person, I can absolutely see us fusing it with our lesser version of ourselves to become more powerful. There has to be some reason we made sure not to leave that crystal behind on the floor.