Frisk was split into Kris and Vessel, and Chara was split into Kris and FRIEND.
>Kris has Frisk's skin and hair colors
>Vessel has Frisk's stripe pattern
>Kris has Chara's clothing colors, stripe pattern and Chara's human personality and relation to Asriel
>FRIEND has the "humble servant/demon that comes" thing and the grinding/9 obsession aspects of Chara