Yukari
>selfish, possessive, overtly mentally abusive, treats her long-time "friend" like shit, but akira actually is okay with this because she's a pathetic doormat who makes battered-wife excuses, so I guess they deserve each other
Meroron
>selfish, possessive, mentally abusive but in a subversive cowardly way, treats her long-time "friend" like an object or personal nee-tama doll and doesn't allow her any agency whatsoever, purirun has no say in the matter

Guys, I think Meroron wins. I think Meroron takes the crown for "actually a bad person" worst personality of all cures.