[Lantern]

Originally Posted by thundrakkon

What I'm curious about is when they revert to child form, what if something traumatic happens? Will it change their personality as if their childhood was affected, once they regain their adult form?

They addressed that issue in here:

Spoiler for comparison with the novel during their first transformation:

Inaba actually considered the same question. What if the child suffers something serious? Illness, trauma, or worst: Death. What will happen?

They never found out... More like, they refused to find out. So they took every possible measures to ensure the safety and health-being of their reverted companions throughout the arc, such as cleaning up the abandoned apartment room so chibi-Inaba wouldn't get sick, keeping a close eye on the chibi x 3 - Iori, Yui and Aoki during that festival so they wouldn't run off and hurt themselves etc.

They succeeded in that aspect, so in the end, the question was never answered.