Drifting Dragons manga volume 15 features story and art by Taku Kuwabara.

The deadly battle with Typhon is over, but the skirmish left Gibbs mortally wounded. He's going to need a particular kind of dragon oil to survive. Luckily, there should be a source close at hand. Meanwhile, Jiro's father reappears after abandoning his son for years. What could have driven him to leave his child?