NIN lore

[YianKutku]

I'm only guessing based on the names, since as far as I can tell the skill icons are too heavily stylized.

"Ten" for "heaven" probably means 天, which is used in the sense of "the heavens", meaning the sky. "Air" would probably be 空, "ku" (or "kuu", depending on romanization).

If you're wondering, "Chi" is 地, meaning "earth" or "ground". (Anime fans might recognize it and Ten from 天地無用, "Tenchi Muyo".) "Jin" is 人, meaning "person" or "human".

Anyway, back to "Ten": I say it's used as "the heavens" because it's also used to signify where the various gods dwell if you're speaking in that context, referring to the portion of the Shinto gods who are amatsu, or the Taoist Celestial Bureaucracy, or some such. However, it can also commonly be used to just mean "sky", ie what you indicate when you go outside and point upwards.