The nine. Aka xurs bosses. They were the ones that gave skolas a ketch and a scorch cannon. Then told him have fun wrecking havoc in the galaxy and getting your revenge on the awoken. My proof is in the legends and mysteries section of the grimoire titled "the secret fate of skolas". But yea were probably gonna have to hitch a ride with xur to where he's from. And then kill the -blam!-ers controlling him otherwise known as the nine