The Horologues are demons and antagonists of the story.
Horologues are demons that feed the time for humanity. When a person begins to feel their regrets and wish to return to the past, their regrets lure out the Horologues. Initially, they might look like granting people's wishes in order to reverse the time. However, what they're actually doing is devouring their time. As such, they cause the flow of time to reverse for the humans they target, and they revert it to non-existence in no time. Horologues' sizes are small to begin with. However, when they devour more time, they begin to increase. A long time ago, the god of time, Chronos, stabilized the flow of time. As such, he fought the Horologues and managed to put an end to the war. However, a small faction of Horologues were still survived. Horologues, however, are able to take on human forms.