A4 will be quietly worrying about her CR (and especially A2), but she's also outwardly optimistic. She will hide her worries with a smiling face! Also, while protected by Astoria's magic, she is a very heavy combat android and has the potential to fall into some holes. She doesn't really care much about the merfolk (at least initially? but she'll be fascinated by the fish, underwater, buildings, etc.) and mostly cares about reuniting with her friends. She will follow others if they intend on investigating/exploring! She can possibly be roped in for spearing marine life too!

And a note on A4's powers because she has fashion powers to generate random clothing based on what world she's on. Her clothing gacha pool might be a little limited this time since the merfolk wear minimal clothing! But they're probably small garments that have plants/seashells/fish scales on them. I'll need to look up some ref pics for ideas...