You can farm him with literally any class… the class that would get there the fastest starting from scratch would be sorc of course. Your gear determines the risk of dying. Barb would be the safest with gear that isn’t that great but getting there will be the slowest out of all the classes. That said, an es sorc can be extremely tanky with garbage gear, that is most likely your best bet. Any spell tree will work just fine. Sins are also really broken and just breeze through the game thanks to mind blast. I’m assuming we are talking about p8 ssf. If we are talking p1, I mean your mind basically needs to be handicapped to die or playing some weird challenge. Any standard build should have 0 issues on p1. And yes, monsters rest in peace works with spells.