I would ask him his reasons and attempt to asses his thought process, in the event that there really was no other way. Then yes. I would end his life. I would also follow him off a bridge, into a burning building, or anything else he needed of me. I have known my best friend my entire life and he is the only person I have ever met who as never made anyone upset, has no enemies, and is known by everyone. Hes a caring man and a great friend. I count myself as among the lucky people in the world to hold the title of his best friend. Yes, i would end his life if he asked me to. but what is more likely... I would do anything and go through anyone to ensure his continued existence even if that lead to my own death. He is a far better man than I.