Using Insurgence sprites in own game

How are the rules on using sprites from this game in your own game, as I want to have a mega Zoroark but I can’t find any Zoroark form that I really like apart from the one from this game, and maybe others.

Is it something I’d have to ask the original artist about or is there a general agreement that they’re for this game only?

Of course with credits and links to the source/artist.

the artists are not active on the forums
there is only one person somewhat active and that is deukhoofd which is not an artist nor a developer
i think that they would allow u to use the art even if they didnt they probably wont know about your game and thus there would be no problem