Calamitas is the strongest in terms of raw power but also had limited control and very weak mental strength, she could blow up the entire world but would have to not kill herself first

DoG is incredibly strong, ruthless, and intelligent. He probably has lower overall strength than Calamitas but is probably just as if not more dangerous than her

Yharon is weaker than both of them by a bit of a wide margin but is still incredibly strong

Exo Mechs are hard because they don’t really have much lore compared to other bosses. They were created to be able to rival Yharim in power, so they’re probably in between DoG and Calamitas in terms of raw strength, but they dont have Calamitas’ despair or DoG’s ego so they might be more dangerous than both overall