Combat Clown works both for those who are intentionally funny, and for the straight laced type who simply goes mad when people ridicule him. Needless to say, this schtick works for hotheaded characters, although the contrast of a normally peaceful Shaolin monk who goes insane whenever anyone laughs at him might be amusing, too. Originally by Kevin Mowery.
It's going to happen sooner or later. You're going to blow a roll in a big way at a critical moment and people are going to laugh at you. In fact, if you botch, you can decree that your character does something unintentionally funny when he screws up. Everyone with Willpower lower than your Charisma laughs at you, losing three shots in the progress. You get +1 to your AV for the duration of the current Sequence. If your description of what happens makes the GM laugh, you get the bonus for the rest of the fight.
What, they're laughing at you and there's not a fight going? There will be...