The Tenseiga (天生牙） is a fictitious sword that cannot cause injury, but instead could only heal wounds. It was created by one of Sesshomaru's father's fangs. It has the opposite effect of its brother the Tetsusaiga. Instead of having the power to kill a 100 demons it has the power to give life to a 100 demons. Sesshoumaru despises this because to use the sword he needs to be able to care for life which he doesn't so he keeps trying to get the Tetsusaiga from his half-brother Inuyasha. Eventually, he uses the power of the sword to revive the head of Goshinki (the youkai who bit through Tetsusaiga) and had the sword Toukijin forged.