Combining recent accounts of him and research on tengu, my vision of Lord Tenma is as follows:
-Black
-Muscular
-Buzzcut, five o' clock shadow (at all times)
-Hair and beard are as smooth as a horse's pelt
-Manly scarf in the form of a Yuigesa, always flowing in the wind*
-A Tokin floats above his head*
-Has wings, but does not need them to fly anyways and can hide them similarly to other Tengu
-Wears a bathrobe, decorated with leaves
-Holds a Hauchiwa fan, is never opened
-Said fan can transform into whatever he chooses. Say, an Oyster with two tickets to that thing you love**
-Wears modified Tengu-geta that appear to double as slippers
-Can easily chew through swords
-Incredibly skilled at hand-to-hand combat
-The Tenma moving at high speeds can be compared to a shooting star.
*The manliness radiating from Tenma is enough to create a field of constant rapid air flow. Likewise, this field can be controlled to the degree of a high-ranking Tengu using their Hauchiwa.
**Because it is never seen open, some believe it is simply a transforming stick.