>>55096401His initial charm was the cute shy boy going full yandere, a very unusual thing for a kiddie game like Pokemon, and on top of that, the reason for his mindbreak was you. It felt personal and people who like him also feel sympathetic, wishing it would've gone different.
The time gap between the DLCs caused a huge wave of fan work speculating on how it's going to be. For me, the freedom of this time period was very special, it felt like anything could be possible. Kieran allowed people to express their wildest fantasies.
Sadly, it all ended up being pretty disappointing, especially for dark Kieran enjoyers. I wonder if his popularity will drop now.