Remove Plague contamination from the human. Set the Endless Void upon him so you may learn. Calm yourself beforehand, at least from the lingering fear from that Barker's mind.
Considerations for after committing this man to the Void:
Don't leave immediately.
We're prefixing our attempt to leave with a request to the Blighted Glass, right (as per ZBridges)? If so, we can can/should take down Dust-rich targets before then.
If not or if she refuses our request, we'll need to time it more carefully, because the Blighted Glass will almost certainly know the instant we seize someone's Nexus.
Other timing concerns: Can we steal the remains of a vessel Sloan can survive in from this Blighted amalgamation, and then use or repair it?
If not, we'll need to leave just as the Glass is beginning her assault on Revati, because Sloan can only survive in our Voidship form for a week, so we'd need to reach a habitable system within a week. Revati system isn't habitable and its stations or craft won't be either after the assualt, but we know it has a gate that should be quick to get to since the Plague are using it to strike fast at the rest of the Network.
Unrelated, we should try to either find out from the Herald where the systems are that the "other Lords and Ladies" are targeting, or try to figure it out from any latent tactical knowledge about the Empyre. (I don't think we'll actually be able to figure it out from latent fragments though, because the other systems are probably unremarkable like Revati, and so possible Empyreal weak points probably far outnumber the other assault forces. We will probably have to ask.)
I wonder why there's an Empyreal defense fleet at Revati. Protecting the Gate, yes, but why establish a Gate there? No habitable worlds, so probably few ways to extract value from the system. The Gate could be there just as a waypoint to other systems, which is also consistent with the Glass selecting it. But I assume Gate travel (for regular Empyreal citizen travel, not this assault) would be easier by just finding a denser network (routing closer to the Empyreal Core.)