Not sure what I'll be throwing up concretely yet but some ideas/ concepts:
Rebecca - Assassin dreams, building off her feelings of not doing enough and or forgetting 'where she came from' essentially. To tip the boat the other way, white picket fence type dream of settling down. Possibly only to realize mid-dream that she's abandoned people to get there & feel selfish. Fighting dreams? Death dreams... losing loved ones dreams. A giving up dream?
Jezebel - Nightmare of going home to Hell. Dragging along a fiance or two to try and fill in the blank of what's she going to tell her father!? He exiled her! She's doomed!
Karev - You bet your baby booties he's going to be a surgeon, work in the peds wing of a hospital and or give anyone pregnancy check ups if you feel you're knocked up.
Logan - TBD; May sit it out or just visit people if inspired.
Peter - Who doesn't love high school flashback dreams?