EIGI: SHADOW SKILL

In the land of Kuruda, warriors with magical powers and incredible fighting skills battle for the ultimate prize: the title of Sevaar, the strongest warrior in the land. Elle Ragu, nicknamed Shadow Skill, is the newest Sevaar to emerge, but that doesn't make her life any easier. Teaching her "little brother," Gau, how to be a warrior, fending off assassins from other kingdoms and thwarting enemy invasions is hard enough, but her biggest challenge will be paying off her drinking debts. (Source: Anime News Network) — Description from AniList community (anilist.co).