I Don't Cultivate Immortality, but Immortals Can't Take My Punch!

[No System + No Female Lead + Invincible from the Start, No Leveling Up + Body Training + Lighthearted + Power Fantasy] Xu Kun transmigrates to the Immortal Realm and obtains an invincible fitness technique. Even the elderly, weak, sick, and disabled people who train alongside him, as well as a big rooster, become overlords in their own right. Xu Kun himself becomes invincible in the world.

Who dares call themselves invincible? Who dares claim they cannot be defeated? None of them can stand before me, Xu Kun. In this vast Immortal Realm, is there really no one who can take a single punch from me?

PS:

Cultivation realms: Qi Refining, Foundation Establishment, Golden Core, Nascent Soul, Deity Transformation, Void Refining, Body Integration, Tribulation Transcendence, Great Ascension;

The protagonist is absolutely invincible!!!