If you're looking for anime similar to Thunderbolt Fantasy, you might like these titles.
Làng Wū Yáo, a boy with a supernatural singing voice, gets caught up in a life or death battle performance against other singers.
Carrying the Sorcerous Sword Index, a treasure said to invite calamity, Shāng Bù Huàn continues to wander the land. After departing his birthplace of Xi Yu and arriving in Dōng Li, he found a brief respite before being discovered by his bitter enemy, Huò Shì Míng Huáng--and now, his life is once again in danger. From the distant west, countless bizarre killers with otherworldly powers assail him... until a strange bard clad in crimson arrives to help.
After annihilating Han, Zhao and Wei empires in succession, the dynasty of Qin is ushering in an unprecedented flourishing age with powerful cultivators emerging endlessly. People take pride in being part of the Qin dynasty. However, Ding Ning, a young lad of humble origin in Changling, Qin, is determined to subvert this dynasty and kill the emperor who breaks in the Eighth Realm.