I ran a short-lived, dimension-hopping campaign in the mid-90s. Only people with a rare genetic factor could project to other dimensions and times, so the PCs were normal folks from 1996 who had been recruited into the time corps. There were four party members, two of which play a role in this story: One was a former stage magician named Mandrake, the other was the male model Fabio. The player running Fabio wrote the character as a knife master and compulsive liar.
The party was taken into custody while exploring an authoritarian parallel world. While being questioned, Fabio began to drop hints that they had information concerning French espionage and the mysterious Brinkmann incident, so secret that not even I as the GM had heard of it. Mandrake, Fabio explained, was a pivotal agent in the Left Flank. Which agent? None other than the infamous Churn.
The PCs managed to escape and were hiding in a greasy-spoon diner. Although Mandrake had loaned him a dagger, Fabio decided they needed more weapons-- like say, kitchen implements-- so before any one could stop him he was back at the grill exclaiming to the cook that he was the famous chef "Pierre Butter-spray" (pronounced in the silliest French accent) and he had come to cook for them. The cook was hearing none of that, when it occurred to the PC running Fabio to ask me if the cook was fat. Yes, I said, forgetting that Fabio also had the disadvantage Intolerance to fat people. Fabio stabbed the chef in the neck, killing him. To escape from security forces, he jumped back to 1996.
The controllers asked him why he had come back. What had happened to the rest of the team? They were in trouble, Fabio answered, but could not concentrate to make the jump back because they were drugged up with heroin. He had only been able to escape because he was immune. Immune? Well, no, but he claimed that due to his long history of heroin use, he had built up a resistance.
He is the only player I have ever seen play Compulsive Lying to such lengths, and amazingly enough the team still managed to finish their mission. Also surprising is that no one shot Fabio in the back, although everyone was sorely tempted.
On a later mission, the team was in a medieval parallel world. Again returning to 1996 without the other PCs, Fabio convinced the controllers to give him a load of dynamite. He went back to the parallel and sighted the other PCs at a guard house. Deciding they must be in trouble, Fabio attempted to sneak into the station. When he was stopped by several guards, he whipped out a stick of dynamite and threatened to light it. The guards, being medievals and knowing nothing of explosives, did not back off. Fabio, thinking they were being tough, lit the fuse and tried to stare them down. When they did not flinch, he tossed the dynamite at one of them and attempted to charge past. The guard caught the dynamite and bodychecked Fabio. The explosion set off the rest of the dynamite, bringing Fabio the end he sorely deserved.
The other PCs, eating lunch in the mess hall of the guard house, only heard an explosion in the distance. The other players, however, were laughing like mad.
Obviously, the real Fabio does not possess a rare genetic factor for time travel, does not lie compulsively, is not a master at knife fighting, and does not actively hate fat people. The episodes described here did not befall the real Fabio. The second picture above is of something that befell the real Fabio, however. In March 1999, Fabio collided with a bird while riding a roller coaster in Virginia.