Angus' eyes were wide as he rocked back and forth on his feet like he was trying his hardest to resist some external force that wanted to push him to the ground. The hole in his head that was gushing with blood did not look to have had the immediate effect of death that Henry had seen Headshots make all his life.
"I—" Angus started to say and then choked as blood started to fill his mouth.
Henry would have shot him again but there were no more bullets in the Revolver. So he walked over to Angus and watched as the 'light' dimmed in his eyes but it still glowed a dull purple.
And then, Henry understood;
For all intent and purposes, Angus was dead but due to his intensive assimilation with the Vinculum, the object was keeping his body standing— Keeping him 'alive' and doing a horrible job at it.