I Cultivate by Spending Lifespan, Slaying Demons in the Demon Sect

Jiang Bai is abducted to a demonic sect and, from the start, has half his lifespan taken away! Fortunately, he obtains the Record of Sealing Demons, which allows him to cultivate immortality by spending his lifespan and deduce cultivation techniques! What should he do when his lifespan is insufficient? Slay demons and exterminate evil to obtain more lifespan! Jiang Bai immediately turns his gaze toward his sinister and terrifying fellow disciples. Minor mastery of Blood Flame Art (requires consuming lifespan and vital essence to cast) -- perfect mastery of Blood Flame Art (can incite the enemy's lifespan and vital essence)