Raikou dream could be similar to Kyogres dream but she would have a hamster wheel to help burn off her excess energy.
Suicune dream would be her as a princess and the MC is her white night that saves her from a crazy cultist and if he cums on her the cum becomes like a white wedding dress or holy armor that makes her happy and the sight of it makes the cultist melt or explode.
Arceus dream could be her playing a top down city builder game on a tablet or computer and getting it just right.
Dialga dream could be a rendition of Doctor Who the time lord and the MC is the companion.