I bought an account a couple months ago. I asked someone to train it and they were hacked by someone who stole all his accs along with my password. They tried to get my account banned but instead they got ti locked. I unlocked it but then the password was changed again. Is it the hacker or the guy who sold me the account? (btw the guy might have set recs while on it)

It was most likely the guy who was training your account who stole it, especially if he knew that someone had sold it to you in the past because it could make sense that the original owner hacked it back.

If the password was changed again, either the original owner is recovering it back, or your computer contains a virus.

most liikely owner

well if it is recovered again ill conclude it was the owner otherwise i think its the guy