The Tengu is a fascinating creature, neither black nor white, it seems to permanently reside in the area of grey (pun not intended).
Back in ancient times when the unknown was a subject of fear rather than a new series on the Discovery Channel, people in Japan believed that forests were a spiritual area, the place where the veil between heaven and earth was the thinnest, so to speak. To venture into a forest was an act of such danger as to be foolhardy. It’s a caution that carries merit to this day but at the time, this explanation gave a more superstitious theory. Forests and mountains were believed to be the habitat of a Tengu (天狗).
Tengus are commonly associated with a mask with a big red nose and white hair. They are most frequently portrayed as wearing the costume of a yamabushi (山伏), basically holy men who live in mountains, studying religion. This outfit included a small black cap and a sash with those small pom-pom balls. They are also seen wearing a Tengu-geta, a tall, geta-sandal with one tooth, a magical fan and carrying a Shakujo (錫杖), a staff used by Buddhist monks.
Tengus didn’t reside quietly in the mountains. They were considered to be very much interested in the human’s fight of power and politics, and considered instigating wars and screwing with history as a source of entertainment. Think Loki of the Norse Gods, only not as good as Tom Hiddleston made it look. Whenever Japan was united and peace would reign the Tengu would lend support to the opposing party, thereby starting up another battle, never allowing that peace to continue.
But, here’s the thing, once upon a time, Tengus were supposedly human. Buddhist monks of high learning, in fact. It was believed that when Buddhist monks achieved a high level of philosophy and thought, when they passed they were rewarded with heavenly respite. But if those priests still hung onto their baser urges – love, hate, all the goodies, if they were vain and carried evil in their hearts, they fell to the Tengu realm and were reincarnated into a Tengu.
It is not to say that all those who were evil became a Tengu. There are many different types, but a basic divide can be concluded. Kind-hearted priests could still became Tengu, specifically, Zen-Tengu (善天狗), basically meaning a kind Tengu. They would provide protection for priests and monks-in-training and punish those who were evil, or who thought to desecrate the forest.
And of course, the vain, evil priests became Aku-Tengu (悪天狗) or an evil Tengu, it’s all very literal. They disrupted priests in training and would plot to drag them into the Tengu realm as well.
It is interesting to note that the Tengu is considered quite high in the youkai ranking, hence the association it has to the forest, considered both hugely spiritual and terrifying. Once a harbinger of war and strife, now sometimes considered a gruff, if benevolent guardian of forestsone might wonder how much their actions as Tengu could be affected by their previous lives as humans.