Asami was so very not joking about his ultimatum before: "I'm going to take Takaba and get off this ship. If that can't be done, I'll blow a hole right through your heads and turn this place into a graveyard"
so it's good to know that he serious. For all that wrath and gun pointed at his head, Mikhail has a bit of a non-reaction. Just a 'hey you shouldn't have done that' but perhaps his composure is part of his strategy for not getting shot. He protests innocence to the 'shooting Akihito' part of the scheme, which is true enough, though he does give away their intent to distract Feilong (who's little sweatdrop shows that at least he's aware he's been foolish this entire ordeal). Asami doesn't start the massacre there and then because... really, why? Maybe Mikhail's 'keep him talking' thing is working, just like in cop shows, or maybe Asami's hanging on to the hope that Akihito isn't really dead
Kirishima has a good recovery time, as expected of Asami's subordinate. He gets back on task quickly, immediately notifying his boss of the update that Akihito is not dead but at least he has something to defend himself. Alternatively, Akihito has a weapon and though he can be fierce this is unprecedented violence. Kirishima marches on, paying not enough attention to the bullet in his torso. The apology is a bit much though, Kirishima, considering that you still protected Akihito and are still trying to do your job
To his limit indeed. Akihito is just do one with all of them. He's done% done. No more Mr. Nice Guy (haha can't resist) he doesn't look very intimidating, not when compared to the actual assassins in the series, but given his usual level and especially relative to his limited action this arc, this is essentially his freest decision since he chose to follow Feilong into that parking garage. He could either hide and alert an authority/call Asami, or he could claim what resources are available and charge straight in. Akihito's done with their shit, and worst of all, they've pushed him to the point where he's pissed off, so no I don't blame him at all for picking up the gun and going after Yuri. dumb thing to do? yes. a thousand times yes. understandable? oh yes.