This jutsu is pretty useful at times, possibly when i would firstly catch my opponent off guard which could be possibly when he's preforming a jutsu with a deal amount of handseals, seeing as how this only requires one handseal precisely the rat handseal its quite a fast tech to preform, trapping him in a skull shaped flamable gas which also plays the role of a mist making the opponents vision slightly unclear, which i will ignite the gas which will transform in a fireball leaving the opponent burned inside.