When Oren gets turned into a baby by Black, there was a catch; Baby Oren would try to kill himself anytime he was left alone. When he went back to normal he was fine, but he remembered none of the events from when he was a baby.

We can take this as coping with suicidal ideation, and while many littles do remember what happens when they're regressed, some do not. Also, his voice goes to a higher pitch, which with some, that can happen. With some, it doesn't, but it can happen.

How about Gray? Can't even talk, he just makes sounds or cries. Verbal loss can also happen. Also, scribbling Wenda on a blank piece of paper. He has a favorite person we need to absorb this like a sponge. Also, he does remember everything that happened.

We could also take their language, or lack thereof, to see what mental age they could revert to. Shockingly Gray would likely be more of a baby, seeing as how he doesn't speak at all.

Yeah ngl this comment has a point

Wait WHEN DID HE GET ARRESTED HUH-

Plushie Gray!!!