If you've fought alongside him then you should know he can defend himself with his fists. He's not the man you knew. There's nothing to say he didn't come from another universe or a different story or timeline and that he's a completely different version of the Sexby we knew. You're taking a gamble that, unlike every twin and the different versions of people we've already had here, he'll be the only one to be himself. That's a gamble that could murder a dozen people before it's stopped and that doesn't bother you?