Angel: After the Fall (2007) #11
Plotted by Joss Whedon and Brian Lynch with script by Lynch and pencils by Nick Runge. Angel has found the person responsible for starting the demon war that ravaged Los Angeles in recent days and is shocked to find out it is Charles Gunn, a man he fought side by side with against the deadliest foes who is now a vampire. Emotionally unstable, Illyria can't help but revert to her Fred Burkle-self at the sight of Gunn. Nina, the werewolf girl, has to take Illyria/Fred back to the Hyperion Hotel, leaving Angel to face vampire-Gunn alone (well, along with a fire-breathing dragon).
Gunn doesn't kill Angel outright, despite figuring out that he's no longer a vampire, but instead reveals that he, Gunn, has inherited the power of visions that used to be Doyle's and then Cordelia's. And in his visions, Gunn sees himself as the hero who fulfills the Shanshu Prophecy, earning back his humanity. But in order for that to come true, Angel must die. Spike, Connor and Gwen the "electro-girl" ride in to the rescue but this tale ends with a treacherous twist that no one sees coming!