Hellhounds cannot be tamed. I believe this is partly due to there being no such content, but also if I recall there's been discussions even on whether it could even in theory be done due to the lore behind what makes them hellhounds. As for pure/corrupt followers, it depends on each follower in question. Some have pure and corrupt routes, like Amily and Jojo for instance. Not all of the them do however. I would suggest poking around the wiki linked below for followers and lovers to see which ones do and how to get them to work since sometimes the method is not always immediately obvious or simple.How do you tame the hellhound?
and is there a way to make pure and corrupt followers be in your camp? I vaugely remember seeing somthing about that at some point....
https://wiki.smutosaur.us/CoC/Camp_Recruits
Most of the time, when such distinctions exist for followers, the pure routes constitute them being lovers and the corrupt routes end up making them slaves, but not always. Again, Jojo for instance has no lover route, but that because his "follower" route substitutes that. His "slave" route is for corrupting him.