It was fortunate that Hermione was with him, otherwise Ron wouldn't have been able to find the distraction that he required in order for him to pull off what he was about to do next. Foot shooting outward, he slammed his heel hard against the demon's toes, right arm hooking around to elbow the black-eyed creature right in the face at the same time. With Hermione speaking up and pointing her wand at the demon, it had looked away long enough for Ron to execute the move perfectly. His hits weren't as hard as he would have liked for them to be - they probably would have been loads more effective if he wasn't feeling weaker than usual from the blood loss - but they did the job well enough. The demon let go of his arm, which gave Ron the chance to dart back and away from him, his own wand rising up to double the amount of firepower that he and Hermione had at the ready.
Magic wouldn't exorcise the demon. Wouldn't kill it, either. But it'd slow it down if they went about it the right way. Mostly, Ron was trusting Hermione to do that. She was ten times better at spells than he'd ever be.
"How many of you are following us now? Where are they?" Like they had much time to ask. For all they knew, the others were cornering on them as they stood there, wasting their time with stupid questions. Ron glanced over at Hermione, nodding determinedly. She'd hex him. Probably had something handy on her person too, like holy water or salt or something. Just enough so that they'd be able to make a break for it while the demon struggled.