expression, godan verb (-ru)
be divinely skilled; reach the pinnacle of skill
Idiomatic expression meaning one's technique has become so masterful it seems almost divine. Often used in contexts like martial arts, crafts, or performing arts.
長年の修行の末、彼の剣術は技神に入る域に達した。
After years of training, his swordsmanship reached a level where it seemed divinely inspired.
神業 is a noun meaning 'divine work' or 'superhuman feat', while 技神に入る is a verb phrase describing the state of achieving such skill.
The phrase combines 技 (technique), 神 (god), and 入る (enter), literally 'technique enters the gods'. The exact origin is uncertain, but it is a classical expression for transcendent mastery.