im also late on this but my idea is this
Blissey (F) @ Leftovers
Trait: Natural Cure
EV: 252 HP / 252 Def / 4 SpDef
my blissey is a counter blissey with light screen to encourage physical attacks. with max hp and def to make sure she doesn't get 1 hit KOed, counter can be a huge nuscence to deal with. toxic is obvious and softboiled is so she can recover if needed, but if you want a more team oriented blissey you could use wish.