What about an international WBF Champion with 27 KOs in 37 fights? Is that a real boxer? Sounds pretty legit to me. What if he was fighting someone smaller than he was? What if he was fighting a guy who was a mediocre MMA fighter at best? Would people die?
Already happened, waaaaay back in the single digit UFCs. Milton Bowen vs. Steve Jennum. Steve Jennum was a police officer and... ninja. No, really. He was a ninjutsu practicioner. Steve Jennum actually won UFC 3, but understand that by today's MMA standards, the guy was a joke. ANY pro MMA fighter in Jennum's weight class would easily hand the guy his butt today.
And the boxer still lost.
And let's not forget James "Lights Out" Toney, who was humiliated by Randy Couture so recently.
Mike Tyson in the UFC. Yeah, if he fought enough and was in his prime he would ocassionally connect with one of his monster hooks or upper cuts and in 4oz gloves his opponent would be twitching on the mat. That would create some excitement. But would it really be THAT much harder than say one of Tank Abbot's wild shots (which dropped 400 lb guys) or one of Cro Cop's left kicks back when that guy was in his prime? It wouldn't take long before his opponents realized "wow, that guy hits really hard" and just started taking him down all the time. Then he would lose on the ground.
But what if Tyson learned a take down defense and some ground fighting moves to deal with that? What then?
That would certainly make him more dangerous. Because now he'd be an MMA fighter instead of a boxer.