I still like Richter, but I never considered him to be the most powerful, strongest, or even most beautiful Belmont.
The most powerful and strong must be between Simon and Julius. I'd say Simon because of his history.
And I already expressed my feelings about Juste.
Someone said (I don't know if in this post) that he resembles more Alucard to a Belmont. But that would make sense, had Legends not be removed from the canon, because Dracula and the Belmonts are related by blood (by the way, it would also make sense in the LoS canon, I'm hoping they include Juste in LoS 2).