'Far more powerful' than
5.428 KT VS the guy who one-shots 28.75 KT beings.
The BFG could potentially vaporize her by itself, negating her (admittedly quite impressive) regen. Depending on the nature of said regen, he may even be capable of incapacitating her physically, and even without that being factored in, she most likely won't even be able to properly damage the Praetor Armor, much less harm the man underneath.
Mobility? Ryuko is clearly superior, but not to any degree that Doom hasn't dealt with before.
Imps, Maggots and other similar demons can travel along walls and ceilings,and the Imps themselves are even shown throwing their projectiles from such places quite easily. More than that, he has dealt with beings that can fly, including the
Revenants who do so using jetpacks. Jump Boots also help with this, if he's allowed to have them.
Her Berserker Mode (assuming such is applicable to her 7-C form) would just make this even worse for her, seeing as it takes away her battle intelligence and basically turns her into a lesser DOOM boss. An unintelligent, animalistic monster is the last thing you want to turn into when attempting to fight the Hell Walker.
Also, he carries holographic projectors which can be used to distract her, and would be especially useful against the Berserker form mentioned above.
P.S.: I assume Doom's amps/powerups are restricted like always, but if they aren't, then the BFG is definitely going to vaporize her once he boosts it with Quad Damage. And with the Berserk Sphere, his strikes would be enough to completely obliterate her.