Anime Series about a boy with reset-button

Question

I remember watching an anime between 2007 to 2014, that centered about a boy that was supposed to be some kind of artifact that could be quenched for a lot of energy, but should he survive till midnight, his body - no matter how badly beat up - got reset to being all fine and fresh and the energy contained within him refilled with a little extra sliver.

The other main character was a girl that acted as some kind of monster hunter or guardian for those that didn't know about the whole supernatural stuff. I believe she thought in Episode 1, that the male protagonist was going to die around midnight and spent the final moments with him.

Answer 1

This is Shakugan no Shana.

I remember watching an anime between 2007 to 2014

Shakugan no Shana came out between 2005 and 2011, so it fits the time period.

a boy that was supposed to be some kind of artifact that could be quenched for a lot of energy, but should he survive till midnight, his body - no matter how badly beat up - got reset to being all fine and fresh and the energy contained within him refilled with a little extra sliver.

The protagonist, Yuji Sakai (the boy in the image), possesses some kind of power called the Reiji Maigo, that replenishes his existence every night at midnight.

The other main character was a girl that acted as some kind of monster hunter or guardian for those that didn't know about the whole supernatural stuff.

That would be Shana, the girl in the image. She's a "Flame Haze" who battles demons from another dimension, and partners with Yuji to protect him.