I had no one to proof read this so any mistakes are mine. I failed English on a regular basis in my youth. I made up names too. There are a few mentions of gore, no really vivid descriptions. Insane!Luffy is fun to write.

Rules

If you have nothing sane to say, don't say anything at all.

Luffy remembers this rule. He remembers it well.

Sometimes he wishes he remebered where he learned it.

He just gives a blank stare whenever he wants to giggle, rhyme a riddle, sing a song, or mention how tasty his opponent's eyes look.

Just like a good sane captain would do. Because a sane captain was to be respected, not feared.

One with questionable mental stability is cause for terror; apparently. Which he found quite strange, why would he hurt his nakama?

Questioning it didn't change the fact that when he opened his mouth to speak the words in his head, he would get the look. The look of fear. It bothered him, it really did, why would he ever hurt his nakama?

They were just him in a different body. One mind and all that. Their dreams, were his dreams, their failures, his failures, their successes, his successes.

Why, oh why, would he ever want to hurt himself?

Why the fear? The stink of terror on his other self's skin?

He had never seen his real crew give him the look, and never intended to give them reason.

It would remind him.

He would never forget his first crew, his original crew. Thankfully, they were not his real crew.

He would never forget how his original crew had stabbed him, again and again.

Put him down like an animal.

He missed them.

Apparently, tearing his opponents apart wasn't an acceptable fighting tactic. It was easy to win when all he had to do was twist the head and pull. Sometimes the spine would come out and stay attached to the head. He had tried to swing it around once and had gotten screamed at for flinging blood everywhere. It had seemed like it could have been a good toy, or flail.

Grab a neck and squeeze.

Rip an arm off and get a quick snack in while his opponent bled out.

He didn't really count the times his enemy bled out as a win, just a draw. Same with goading his opponents into suicide.

He did enjoy tearing open the hearts of people he had felt were truly evil. Breaking their mind was as good a punishment as death. Some people deserved to die.

Some deserved to live in a hell he had made just for them.

He'd never had any trouble with devil fruit users until he started trying to punch them.

But his original crew thought he was wrong.

So they killed him.

He really did miss them sometimes.

Because after them...until he had found Zoro and Nami and Usopp and Sanji and Vivi and Chopper and Robin and Frankie and Brook...he had been alone.

Thinking on it, he still thought it was weird no one ever mentioned his other wanted poster.

Maybe they couldn't tell it was him?

He had wanted to use a cool pirate name, and Bumi had said he acted like a mad dog. So he had called himself Mad Dog Luffy. The poster hadn't mention his name, just called him Mad Dog, he had pouted over it for days.

A bounty of 45 million wasn't that unusual for North blue, it was a rough sea.

He had been confused when he had gotten a new, lower bounty after defeating Arlong. Then again, his old poster hadn't looked very good, just a partially blacked out picture of his face, covered in blood with his mouth around a piece of meat wearing a watch.

He had felt bad for Hat, it deserved to be in his wanted picture with him. Unfortunately his precious hat was nowhere to be seen on the poster, not even in the description.

He had been sure to smile at the photographer for his new picture, hat was in it too, so it was alright.

It was still weird.

He had gotten his first bounty when he sailed into the North waters looking for a crew to go to the grand line with. He hadn't intended to end up there. It had just happened. It made him want to giggle a little, he had sailed the sea Sanji was from. How neat was that?

He bit back the giggle. Given his currant situation it would look not sane.

Which was bad.

His mind dragged him back into his thoughts. He remembered how he had amassed such a great crew. Small like his real crew, but not as close. They had always seemed a bit more selfish, but no less devoted.

They had traveled together for almost a year.

Until they decided he was nuts at some point between the seventh or twentieth person he snacked on.

He really should have found a chef sooner, by the time Megan had been recruited he had hardly liked cooked food anymore.

Thankfully, Sanji knew how to cook meat so it was still nice and bloody.

What had Kilo said?

"A mad dog can still be a good dog, but that don't make it any less dangerous."

He had said that when Luffy had been wrapped in sea stone chains.

Then his back had been stabbed repeatedly by Batra. She had been sobbing. It had hurt.

Batra has always fought well with a sword. She would never be as good as Zoro, but she had that spark of talent.

He didn't stayed dead from it though.

He never did.

After he had dug himself out of his seashore grave he had eaten anything and everything that moved in a frenzy. He had no idea how long it was until he had been able to stop eating.

When he finished, he cried. He didn't want to be alone.

So he had gone to find his crew.

He had found them on the outskirts of the town they had docked in, drinking. When they saw him they had looked horrified. They had said so many things to him. To bad his ears had been clogged with dirt. All 6 of them had looked tired, hungover and defeated. He had offered to beat up whoever had hurt them, kill whoever had made them so sad. They had all started sobbing and yelling incoherently, though that could have been the dirt in his ears again.

Kilo had been wearing his hat. But Kilo was nakama, so he hadn't minded.

Then they went and killed him again.

He let them.

They had been kind enough not to bury him this time. After he repeated his feeding frenzy he went down to the docks to track down his ship, The Fierce Sister. Bumi had built the ship himself over the course of several, long, hard years, as he had told the crew time and time again.

Luffy missed Sister almost as much as Merry.

He had quietly taken his hat back. It had been on a funny little table with burning, smelly sticks surrounding it, then he left. He wandered the water in a small boat for a long time, a really long time. He cried all he had he had in him. Then he had faced a whirlpool.

Sometimes he wondered about his old crew. He always remembered them in times like this. When he was forced to remember his Rules.

Because this marine would be so easy to kill right now.

His neck was right there. One bite and he would be dead. The only other marine near the far wall would panic, then, if he played his hand right, get angry. Say by some well placed taunting? Then Luffy could pounce. Knock him down fast, breaking his neck by stomping on it and not holding back. He had the goddamned keys on his belt, he could see them. But no. He had the rules for a reason.

His real nakama, his real crew, where in the cell with him.

If he had nothing sane to say, he wasn't going to say anything at all.

Or eat people, but that was rule number 2