The shinobi sets themselves on fire by raising their body temperature to ignite the oil in their skin. Using this technique, the shinobi comes in contact with their target and engulfs them in a burst of flames. This technique is capable of incinerating a large group of people and large targets such as the Sōshin. This seems to be Gabimaru's preferred method of finishing off his opponents.
The drawback to this ninjutsu is that if the shinobi's body has severed too damaged then they will suffer the risk of burning themselves as well in the process. When his opponent causes him to be on the verge of death, Gabimaru would ignore this drawback and try to kill them along with himself.