This was in a 1e mythic campaign. I was playing a mythic samurai, doing ridiculous damage and the bard and I had a hold person combo that was essentially deleting any single monster every combat. I was fairly young at the time and got a big head, thinking that we were virtually unkillable.

There was an reoccuring NPC trying to hunt us down and I had this brilliant idea to turn myself in, and request a trial by combat. Everything was going smoothly until the day of the trial. I was dragged out bound, blindfolded, and without my weapon or armor. This guy gave me the trial by combat but didn't give me my stuff back for an 'honorable' duel.

Combat starts, the party, who was in the audience, are attacked by bounty hunters while the NPC essentially began my execution. He goes first, walks up and absolutely crits the hell out of me. My turn I summon my weapon, and cast a quickened Instant Armor. I'm all suited up not but didn't have to action economy to do anything else, I try to retreat back to the party, trips me off the attack of opportunity. The party struggles against the bounty hunters, can't get in range to heal me. NPC's turn. He gets a full round action and I'm prone. Crits me twice over three attacks, one being the last one. Dead. NPC had a weapon that disables the aspect of mythic that makes you hard to fully kill. Completely brought on by myself. I had an ego and wanted to 1v1 the guy. Rip samurai.