Mastering the Recovery Spell Suddenly Makes You Invincible 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

Ling Fan, a time-traveler from the world of immortal cultivation, had extremely low aptitude for immortal cultivation. He could only combine his own knowledge and intensively research recovery spells, and use other immortal cultivators as experiments. He unexpectedly became an invincible immortal cultivator.