Akra immediately starts blaming Aria for what's occurred, because Aria looks the most "official". Dox and Ry faintly recognize each other and sort of huddle together to wait for the chaos to conclude. Crimson stands awkwardly in the corner. Aria eventually kills Akra in self-defense, and Dox and Ry continue to band together. Once Akra's dealt with... the lot quietly discuss the implications of Akra's death, and whether it was justified.
Mir, Demetrius, and Purple Palm talk for awhile, none of them thinking to check the door to see whether or not it's locked. After awhile, when they try to leave and realize it's locked, Mir and Demetrius work together to punch the door down. None of my characters really jump to "violence" as the first answer, except maybe Demetrius, but nobody's paying him to fight the people in the room so he thinks it'd be a waste of bullets that he could eat instead. They don't taste as good after they've been fired.
A handful of my lesser known characters immediately die of cuil underexposure. Dave gawks at the alien corpses. CE, realizing they are trapped in a room with Dave, immediately has the visitant equivalent of a panic attack and starts flinging themselves at the door. Archie plays video games on her phone. Judith, Kera'tiv and Idril avoid everybody else at first, but end up talking to eachother eventually and they all become fast friends. Cantor and GS get into a very quiet argument in the corner. Dave, not realizing that they're trying to escape him, starts cheering CE on. By the time they all get out, CE is shaken, Archie and Dave feel perfectly fine, Cantor and GS are slightly irritated and Kera, Idril and Judith are already planning their first "girls' night."
Esas would probably kill Zarta since she's a shifter and in such an enclosed space he has far more advantage in a fight. Adela would be trying to find a way to slip away from the chaos while Gary doesn't intervene- he hates shifters too. Considering what Gary knows and Tanze though- those two will either have a tense and alien conversation, which could break into a fight of its own. And even I don't really know how that would turn out, it could go either way. Bobby john, my not-character vigilante just casually mops up the mess. Adela and Cardice would probably get along just fine, though I don't know if they're friend material, especially since the presence of Moonear and RH might put Cardice off, whereas Adela would do well with those visitant. Though to be fair friend-making is hard when murdering is happening, which is going to leave the rest tense regardless. I can't really think of any other characters relative enough to include. Sato and Tart maybe, though they're probably going to get high on something in the far corner of the room and gossip about the people amidst the chaos. I have a few more characters that I *could* include here, but they're either secret or don't really add anything. Not too much thought put into this honestly. Though a decent few of my characters would murderously hate each other as I've spelled out here.
Chalk, upon finding out the door is locked would just sit in the corner panicked, constantly calling Belle. Poly would just sit on a couch, bored, watching people trying to tear down the door. Loura, Saoi, and Snipe would all be bashing the door individually with little to mild success. Digit would be filming them all trying to tear down the door. Kaui is trying to figure out how he got there. PB is calling his goons, while Mint is dead in the corner. Alou is relaxed and speaking with the young child from Baldr's underground. And Whirlybird would be outside watching them all through the window.