The Great Mage Returns After 4000 Years is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The worst student of Westrod Academy, the disgrace of the Blake House. A new soul enters the lifeless body of Frey Blake, the boy who couldn’t handle his painful life and chose death instead.

“What’s with this body? I’ll have to check every little detail of it.”

English Translations By Reaper Scans- Support Them on