Constantine the Great — he repented of his sins and was baptized at the end of his life.
Theodosius the Great — he made a public penance of his sins.
Plucheria — Empress and Saint.
Marcian — Was generally a good emperor during a difficult time.
Maurice — A great emperor and possible martyr.
Just off the top of my head.
Agree - sort of with Constantine & Theodosius if we allow “all those things I did to get where I am - Sorry I did them!”
The other three I don’t know enough about to have an opinion.
Late Classical\Dark Ages was a tough ruthless time, one usually had to be equally so to survive, more so to prosper!
Of course there are always acceptations!