AR and AP/RN from web manga Nakanaide maou chan
 

English title "Do not cry little demon lord" is a story about a party of heroes defeat the demon lord's army but then when they finally reach the demon lord Astalolin, they meet a tsundere loli. The heroes are max level and strong enough to defeat her, but they can't deal with her cuteness and don't really want to kill her.
here is a link for the manga
https://cycomi.com/fw/cycomibrowser/chapter/title/68
Since there is a lot of images i will just post the links

Chapter 14 "Charm point" AP/RN the demon lord uses an artifact that allows her to become an adult
here is the demon lord
http://puu.sh/BSjKc/67070dd493.jpg
AP
http://puu.sh/BSjxK/a6e8449158.jpg
they destroy the artifact and get she RN
http://puu.sh/BSjLU/c5c2c15008.jpg

Chapter 22 " Demon castle kindergarten " AR, male baby AR one of demon lord minion uses a magic that regress the heroes both physical and mental for weaken them, but they still keep the same power even as child
AR
http://puu.sh/BSjku/cd3c69764e.jpg
male AR
http://puu.sh/BSjnB/cf14f098a2.jpg