Cultivators seek to transcend realms because they wish to become immortal, to live eternally between heaven and earth.
To achieve immortality, one needs formidable martial prowess, otherwise how can one protect oneself and break through the void to achieve eternal life?
Martial prowess is the standard by which a martial artist's strength is judged, while realm is the standard by which a martial artist's lifespans are measured.
To Transcend the world and witness eternity, both realm and martial prowess are indispensable!
However, sometimes martial prowess is the ultimate standard, since martial artists live for ages, and martial masters can live to a hundred years, not to mention those exalted Immortals.
Most martial artists pursue the ultimate in martial prowess, but those whose lives are drawing to a close crazily seek to enhance their realm to extend their lives.