Permissions To Use Sprites?

[Spyro]

I'm thinking of possibly making a THPP game, not a Romhack, just a game in Game Maker 8. I plan on including every puppet that is in the Touhoudex so far.
(Including the ones that don't appear in the Romhacks such as the DDC cast and Transcendant Maribel and the lot.)

The only question is, are these sprites free to use? If not, who should I ask for permission to use them?

[EXSariel]

A large majority of the sprites are Hemo's works, and as far as I know, they're free use as long as credit is given. Any sprites that don't appear in official you're going to have to source yourself and see since I haven't bothered making a proper credits file yet.

[Spyro]

Alright, thanks for the info!