What is The Eye doing?

[Zohar_Lahar]

Probably Hresvelgr. Or perhaps Haldrath.

[sciencebot]

It's Iceheart crouching behind a snowbank and yelling "HEY DUDES, CAN YOU BE COOL FOR JUST ONE SECOND"

[Nalien]

Probably Hresvelgr. Or perhaps Haldrath.

I'd go with Haldrath, given he was kept in an sort of undying state while directly connected to the eye twin... Plus, you know, he'd have plenty of reason to lament the rift between man and dragon, given he helped create it... Last we ever saw of him (via Echo) he was set to bear the sins of his father until death, so he was certainly under no illusions that what they did was somehow just...

[RobinMalvin]

Whose voice?! Nidhogg's?!
Or was it possibly Hraesvelgr's, since I think Nidhogg would've had Hraesvelgr's eye by this point?

For now, I'm going to entertain the idea that Nidhogg wanted us to be bros.

Nidhogg did have one of Hraesvalgr's eyes since he lost both of his own so it's possible that the voice is Hraesvalgr's and by extention, Shiva's, assuming the voice comes from the eye.

Or maybe the voice is from the soul crystal, which means it could be Haldrath's, or one of the previous Azure Dragoons before us.