He only goes back to life if you hit him again after killing him. when the fight is almost over, make sure you use a single hit attack (example: Melio Fascia instead of Nitesco). When you beat the Jiang Shi, it will have that piece of paper on its forehead - this is a nice little shout out to the mythological monster, of course. But that's how to keep the Jiang Shi down.
if you want to kill him quickly without using OP combos or POW glyphs i used the vol luminatio as main, melio scutum as sub and the volaticus in support just in case you dont get out of the way by jumping. also i had one death ring and the heriophant. simply block the ball of energy and absorb the glyph then cast lum backstep loop till you reach wall double jump over him rinse repeat it takes a while but its a bit more satisfactory beating him in a legit way without getting hit.