His stern face and stoic demeanor belie a calm, gentle man. He is of few words, rarely speaking out unless spoken to, but is polite and understanding of others. Due to his background from Duscur, he is used to the disdain many people have towards him but is usually not too bothered by it.
Due to Dimitri sparing him from the Tragedy of Duscur, he owed him a life debt and is completely loyal to him. to In his support with Felix, when asked if he would obey any order given by Dimitri, he stated that he would and would give his life to protect him. Even if Dimitri would order him to slaughter innocent lives, Dedue affirms that he would do anything he requested, no matter how heinous.
He likes flowers and gardening, but dislikes anyone who tries to harm Dimitri.