Perturabo says he has made another copy of his Cavea Ferrum for the eighth legion (night lords) to "have his sport with.... a uniquely capable prisoner" (page 56)

I was just wondering who this is?

It is heavily implied in some other books (Betrayer) that this is Vulkan. Mightve been Angron, I think a traitor primarch referenced that "no one wants to be Vulkan right now)

This would make it the first ever official art work of Vulkan then! And I gotta say, I think he looks pretty epic.

For those of you who aren't sure on the plot for Vulkan Lives, this is from Nick Kymes blog.

Quote:
Q. Vulkan Lives. Other than the obvious, what can we expect from this?

Without giving the story away, it’s a two pronged narrative in which a double storyline interweaves with the other. It features several primarchs, most prominently Vulkan and Konrad Kurze, and as such the story examines the relationship between these two characters, chipping away at the psyche of both. There’s the return of some classic characters from the series (not all mine, it has to be said) and very little of the story itself is set on Isstvan V, although the resonance of what happened there does inform e narrative to a large degree. ‘Vulkan Lives’, ‘Scorched Earth’ and ‘Promethean Sun’ all connect. And my final little reveal is that this novel leads in to Dan’s ‘Unremebered Empire’, which directly follows it on the schedule and sets up a major story thread in that book.

All but confirms the link between these two comments by Perturabo and Angron in Angel Exterminatus and Betrayer respectively.
Angel Exterminatus:

Quote:
‘The Cavea Ferrum was nothing more than an intellectual exercise for the Firenzii, but I saw how it could be turned to defensive purposes, its geometries used to lure an unwary enemy into a foolish assault, trapping them in a way that would allow no escape.’
‘It’s impressive,’ said Kroeger. ‘Are there any others like it?’
‘Yes, there is one other,’ said Perturabo, almost reluctantly.
Forrix hid his surprise. He had not known that Perturabo had crafted another such labyrinth, but in the frenetic aftermath of massacre of their brother Legions, there was much he did not know of his primarch’s activities.
‘Where is it?’ asked Falk. ‘On Isstvan V?’
‘No, it is not on Isstvan V, it is aboard a gaol-hulk belonging to my Eighth Legion brother,’ said Perturabo. ‘I built him an imitation of this labyrinth in which to have his sport with… a uniquely capable prisoner.’

Betrayer:

Quote:
Angron’s face wrenched again, at the mercy of misfiring muscles. ‘What primarch ever needed guarding by lesser men?’
‘Ferrus,’ Lorgar said softly. ‘Vulkan.’
Angron laughed, the sound rich and true, yet harsh as a bitter wind. ‘It’s good to hear you joke about those weaklings. I was getting bored of you mourning them.’
It was no joke, but Lorgar had no desire to shatter his brother’s fragile good humour. ‘I only mourn the dead,’ Lorgar conceded. ‘I don’t mourn Vulkan.’
‘He’s as good as dead.’ The World Eater smiled again. ‘I’m sure he wishes he were.'

I think we can quite safely assume that a large portion of the novel, if not the main plot line, will be Vulkan imprisoned within the maze by Curze and trying to escape, whilst possibly being hunted by the Night Haunter. If this is done well, it could be fantastic and have some very tense scenes.

Despite my mild dislike of Promethean Sun and Kymes other Salamanders work, I'm still very much looking forwards to this.