Rebirth of the Immortal Venerable

Rebirth of the Immortal Venerable is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here.
The Summary is
After over hundreds of years traveling all around the universe, our main character, Chen Mo has come back to his highschool years. With all of his cultivation gone, he decides to focus on getting his cultivation back and try to find his little junior sister who also died in order to save him!