As soon as at least one second of the first round passes in a professional MMA fight that Sean has with one of these people, their option will resolve YES.

When Sean O'Malley announces his retirement from MMA, all of the other answers will resolve NO. If he dies before this happens, all of the other answers will also resolve NO.

I'm aware that people sometimes come out of retirement and have more fights afterwards, but for the purposes of this market we will take Sean at his word if he announces his retirement.

Any MMA fight must be a professional bout in order to count - an exhibition will not count for the purposes of this market. A fight under boxing rules would not count for the purposes of this market.