From Aka Tenshi:

*Flashback*
1875. Aka-Kenshin from returned from another successful assassination. All he wanted was a good hot meal and to go to bed. But soon, there was a change of plans.
When he made it back to his house, Aka-Kenshin found a young messenger boy waiting for him at the door. Curious, the then fallen angel walked over to him. “What are you doing here?” Aka-Kenshin asked in confusion. The boy didn’t answer. He just handed the black scroll to the fallen angel. Aka-Kenshin took it without warning. He tore it open. The messenger boy stood on tiptoes to get a better view of the scroll. Here is what it read:

You and I have a score to settle. Meet me out in the rice fields by midnight and come alone. Tell anyone about this, you’ll be found in the sea of blood.

Aka-Kenshin couldn’t help but snicker in amusement. The messenger looked at him as if he was crazy. “A challenge to a duel, huh?” the Angel Killer replied. He blew on the tip of his finger hard. He lightly touched it to the black scroll and dropped it fast. The message instantly caught flames. Aka-Kenshin smirked to himself in pride. “Well then,” he replied. “I accept my opponent’s challenge!” The messenger boy’s eyes grew big with fear. “My lord!” he cried out. “It could be a trap to kill you! Are you sure you want to go through with this?” The fallen angel turned to the boy as if he was crazy. “What are you still doing here?” he asked flatly. “How much do I owe?” “Nine coalpince.” the messenger boy replied. (Coalpince is hell currency. And nine coalpince= $1.80.) “Fine!” the Angel Killer snapped.
Then, Aka-Kenshin reached into his black sash and pulled out his black leather coin pouch. He pulled the leather string free and reached inside. The fallen angel pulled out nine dull silver coins and handed them to the boy. The messenger took them with a pale face. He decided to get one last full look as his customer. After moments of staring, Aka-Kenshin barked in annoyance, “Well, get gone now!” The boy nodded in terror. “I wish you luck, sama!” he called with a bow. Then, the messenger boy ran away as fast as his little legs could carry him. Aka-Kenshin shook his head as he watched him leave. Then the fallen angel headed off to the abandoned rice fields.
Oh, if he had only listened to that little messenger boy. For the next events would be tragic. Aka-Kenshin stepped into the center of the rice paddy. He looked around slowly. No one was in sight. The fallen angel couldn’t even sense anything at all! Aka-Kenshin began to wonder if this really was a trap when he heard snickering in the distance. Aka-Kenshin turned to the front in a snap.
Doc was walking towards him with smirk. He was dressed in his battle black and wine red robes. H e didn’t have his usual battle sword with him. Right away, Aka-Kenshin could tell that something was way off!
“So Doc!” the fallen angel snapped. “I don’t see why you couldn’t challenge me to a duel in person. Are you so scared of me that you send your whipping boy out to me? That’s very tragic of the leader of the Rat Pack!” Aka-Kenshin then laughed aloud. Doc said nothing. He just snapped his fingers together loudly. A thousand electric worms attached onto the Angel Killer’s body and began shocking him like crazy. “AHHH!!!” he screamed out in pain. Doc just stood there grinning.
“You’re very tragic for coming out to the rice fields for a duel. Angel Killer!” Doc called back. You see, rice fields are water battlefields. Lava warm water battlefields. Doc knew this all too well. He was the one who set the trap.
At long last, Aka-Kenshin fell backwards. Doc casually walked over to his fallen victim. He grinned in satisfaction. The fallen angel began talking again, but Aka-Kenshin was far along the paper-thin line of life and death, that he couldn’t what he was saying. The last thing the dying fallen angel could remember was the clear and bright stars above as his so-called friends beat him to death.