What? You really need to go back and read thoroughly.
There's no topic of dysphoria at all. It's just a simple fact that my reapers shifts personality when they transform to their reaper form.
Sui isn't unhappy about her loli form. She's just embarrassed that she turns tsundere when she's originally assertive.
And idk if you realize, but there's branching routes for the other reapers. You said you only went trough the "whole" vn once and only talked about Sui.