He did become God Emperor Doom before, so pretty powerful. Dr. Doom is Fortnite is pretty much Dr. Doom of Earth 616, but with a whole lot of power.

Yeah I know. but how powerful is 616 Doom in the current era of comics without boost of powers ? that's what I want to know. I already know Absolute Doom in FN is 616 Doom, but empowered.

Doom is very intelligent. He (like Iron Man) can create his own weapons and suits. He also (like Dr. Strange) uses magic. He rules the entire nation of Latveria. He was a member of the infamous Cabal. During the OG Secret Wars, he temporarily had the Beyonder's powers. That tells you how powerful he is.

in his normal state, what character he can defeat easily, those around the same level as him and those he can't defeat at all ? (Without stealing powers)

Pretty much anybody.