Mullvad got rid of port-forwarding so it's not good for torrenting anymore. IVPN, which is where the Mullvad refugees fled to, just got rid of it as well. I think AirVPN is the next option people are flocking to, but who knows when they'll do that next.
I've also seen stuff about torrenting over I2P which shouldn't have this limitation, but I'm not sure how usable it is right this moment.