This panel was fun as I got to dig a little more into the undead agenda. Nathanos flatly explains that life is not a limitation for consideration; they can bring them back through undeath and continue the torment/truth extraction process. Truth and life being separate and not necessarily related goals is a deep philosophical point. Often, truth leads to death from others who seek to manipulate it for themselves or deny it for their own gain. So while the truth may set you free, you may not enjoy a long life obtaining it (I guess it’s a quality vs quantity sort of thing).
In the interrogation, the teleport augmenter is set off by speaking the name of the keystone, “Hellscream’s Vengeance”. It was a tripwire that shouldn’t have gone off but under the delusion he was hallucinating, didn’t think about it. It released a shadowfel plague into the goblin and charged up an opposite amount of void and fel energy, causing him to explode violently.
Had the multiple anti-magic shell/shields been in place, it would have ripped through the floors of the Hall of Wolves, sickening and killing many. That event made it all the more difficult to conceal so it made sense for them to share what they learned.