Yo guys, I found AR in chapter 71.2 of the manhua (Chinese manga)
Feng Qi Cang Lan.
Hell if I know the full context, but a girl commited some things that warranted punishment or something, which would have caused her grandfather to be exiled. So the female protagonist gives him a pill to feed to his granddaughter, transforming her into a baby and giving them another chance; good thing or bad thing (the girl certainly doesn't seem to be guilty of anything, out of context), I have no clue.
The AR is relatively quick, but it does have process at last; we can see a glimpse of her head becoming smaller, and see her hand shrinking into her sleeve, leaving her as a baby in oversized clothes. It's confusing without context, but very cute.
https://timelessleaf.com/2018/05/29/...er-71-2-extra/