Hangyaku no Soul Eater
Revenge of the Soul Eater: Cast Out as a Weakling by My Sword Saint Father·反逆のソウルイーター
A young man named Sora Mitsurugi is rejected by his father, a famous sword master, and left without a home or his engagement. He travels to the mainland to become an adventurer but is betrayed by his new companions, who use him as bait against a deadly creature. On the verge of death, he gains a powerful ability and transforms into a legendary dragon known as the Soul Eater. With this new strength, he seeks vengeance.