Leonard has been stabed by Death so Finn and Ghost have to destroy Death to avenge Leonard.
Day 1 - The Beginning of deathEdit
In the grasslands of Ooo, Leonard was busy shooting targets when he was ambushed by Death, Ice King and The Night Owl. He easily defeats Ice King and The Night Owl but was stabbed by Death in the chest.
He winded up in the hospital and the only people that heard about Leonard's death were Finn, Ghost, Marshall Lee, Ricky, Marceline, Marty and Richard. They all come to Leonard's bedrest.
Finn: I'm sorry bro, I wasn't there for you.
Leonard: No Finn, This was my fault that I died.
Marceline: Leonard, you gonna be alright, so just stay here.
Leonard: It's too late for that. I'm near Death now, and I'm pretty much screwed up. But, there something I wanted to tell you...
Marceline: What is it?
Marceline:(sobs) I love you too, Just Please don't die.
Finn: Yea Leonard?
Leonard: What time is it?
Finn: Adventure Time.
Leonard and Finn do the fist punch for the last time then Leonard dies and drops his sword on the floor.
Ghost: I will wield his sword...until he is avenged....
To Be Continued... for now... MWWAHAHAHAHA!
Day 2 - VengeanceEdit
Everyone shows up at Leonard's Funreal including The Assassination Society Leaders (Ghost, Roach, Marty, Richard) and The Great Hero Billy.
Billy: Sorry about your brother, Finn.
Finn: It's okay; though Marceline is in room, seriously crying over Leonard dead. Did you met Leonard when he died?
Billy: Yeah, and there something I want to discuss with you.
Finn: What that?
Billy: He's said to tell you that he was ambushed by the Night Owl, Ice King and Death.
Finn: Oh my glob!
Billy: He easily defeated the Ice King and Night Owl, but was easily killed by Death when he was about to perform the Slashing Stabber combo.
Billy: Duh, besides that techique takes years to master.
Finn: Then I vow to avenge Leonard by killing Death by honour of my brother's good name!
Billy: Yeah, You go, Finn.
Finn: Let's go, Billy!
Billy: Oh sorry, Finn. I'm on conucil duty, so you're on your own.
Ghost: I'l go with you, Finn. Besides I've been waiting for this moment.
Finn: Ghost! But why?
Ghost: When I heard about Leonard's death, I was so depressed. He taught to be violent again, so count me in!
Finn: You're In!!
So Finn and Ghost embarked on a journey to avenge Leonard, when a mysterious man with grey spiky hair, a blue left eye and a red left eye and a big sword gets a call from his phone while hiding under a bridge.
Death: Yes, It's me.
???: Is Leonard dead?
Death: Yup, I killed real good! BWAHAHAHAHA!
???: You're an idiot.
???: Don't you know that his pitiful friend wearing a dumb hat and my bro Ghost going to avenge Leonard. This wasn't part of the plan.
Death: Sorry, Boss. Don't worry, I'll get rid of them.
???: No need, we're talking Ghost. THE Ghost. He'll cut you down right before sneak attack him. I'll deal with them myself. Their quest will lead to their demise.
Day 3 - The BloodedgeEdit
That mysterious man on his phone was Ragna the Bloodedge. He was the leader of a society called the SS - Class Criminals.
Finn: That guy looks ... familliar. He might be ...
Ghost: Ragna the Bloodedge.
Ragna then notices Ghost and Finn.
Ragna: What do you want?
Finn: On how your servant killed my brother!
Ragna: Oh, you mean Death?
Ghost and Finn: YEAH!
Ragna: Then you deserve a fight.
So the three use their swords and they all clashed. Too many strikes, too many slashing and too many hits. By then, Ragna performs his Inferno Divider counter move on Ghost.
Ragna: INFERNO DIVIDER!
Blood comes out of Ghost.
Finn: YOU WILL DIE!
Ragna gets his arm cut off.
Ragna: MY ARM!
Finn: You will regret this.
To be continued...
Last Day - EndgameEdit
With Finn on his own he makes it to the Undead Kingdom, He encounters Death.
Finn: Let's end this.
Finn kills Death.
Death: No...We cannot fail...
Finn: Yes! I avenged Leonard!
Finn heads to the Candy Cemetery when he sees nothing but a guy with armor.
Finn: Leonard? Is that you?
Leonard: Yes. I've been avenged like you did so. I was revived with cyclops tears.
Finn: I will never let you die again.
The moral of this story is to kill the leader of a evil team after avenging.