Honestly, what sucked about the battle was the forced tension, or more accurately, the nonsensical way it was set up. When I first saw her, my first thought was that she was an ultra strong demon who's power level could rival the MCs. But as it progressed, we find out that she's the adventurer who had a level way below Tomoe's??? And maybe I should start reading the LN cause this manga is doing a piss poor job of explaining the MC's powers and limitationa. Like no one here is 100% sure if the rings are power inhibitors or not, it's just a guess about why the hell is he all of a sudden stuggling against an enemy who's weaker than Tomoe. If you're going to do this sudden change in how the battles go, at least use a character/situation that allows the readers to easily understand why the dynamic is different. The fingers might be pointed out more in the LN, but it's still a weird way to explain why his OPness is no longer as effective.
Basically, why the hell did they use a character that they established as weaker than the servant of the MC for such a battle as this?