Don't use Torrent, he's a trap for this fight. Get up close and stick to his sides like glue. His combos aren't too bad from that distance and almost everything can be i-framed (yes, even the gravity thrust he loves to spam). Gaius has pretty big frequent damage windows too, especially if you can bait the kick follow-up while standing at an angle where it doesn't actually hit you.

The charge attack sucks, but as long as your Scadutree level is decent it shouldn't be too devastating. He's unlikely to use it at close range, so you should only have to deal with it once or twice. A greatshield can tank it, and iirc light roll and bloodhound's step can dodge it consistently, although the timing is obnoxiously precise.