"Angel with a Shotgun" by the Cab
Vash was pissed. Who in the world had gone so far as to shoot Lilli?! He vowed, out of love for his little sister, that he would avenge her. He was a fallen star now, an angel that would kill all who stood in his path. If he found the killer, he swore to kill him in the most painful way possible. But he didn't realize that, by doing this, he was severing any hope of seeing his little innocent sister ever again. Because fallen angels never got re-hung in the sky. Bet he didn't care if Heaven wouldn't take num back. She was all he had, and someone had torn that away. He was starting a war, and he knew exactly what he was fighting for.
Vengeance.