^THIS
Anakin/Vader is the most miserable person alive (at least until Empire Strikes Back when he starts having fun with the sheer terror he inspires in people). At the point where this story takes place, when he's either witnessed or actively contributed to the death of anyone who's ever cared about him, I totally believe he's ready to kill himself at the drop of a hat. He was probably secretly hoping the lightsaber took out some essential life support functions.
I clearly need to read this comic because I'm a huge fan of anything that harps on how wretched Anakin is. My obsession with this idea led me to make this: http://www.youtube.com/watch?v=2xg3q39loZQ