These are divine artifacts granted to humans. Issei possesses the Boosted Gear , a Longinus-class weapon inhabited by the Welsh Dragon, Ddraig. Watching Issei "Boost" his power every 10 seconds to overcome overwhelming odds is a staple of the show's hype moments. The Characters: A Heart for Every Trope
At its core, the series follows Issei, a "perverted high schooler" who is reincarnated as a Devil by the beautiful Rias Gremory after being killed by a Fallen Angel. He joins the , which is essentially a front for Rias’s peerage. While his initial motivation is simple—become the "Harem King"—the world around him is anything but. High School DxD
While the show is famous for its content ratings and explicit visuals, the characters are surprisingly well-developed. These are divine artifacts granted to humans