Where tf did they even find someone like my abel

First, you gotta make 'em scale a cliff, repeatedly. This is crucial. Apart from that, a little trauma and a dash of madness seems to do the trick; when they turn to radical kindness to counter a world that is anything but, they're about done.

In case of the imposters I suppose they stored a mold somewhere to just replicate the King's Regas to slowly but surely drive them mad.