After 100+ attempts with different builds and weapons I totally cheesed Malenia with a level 25 brass shield, black knife tiche and rock sling.

This almost felt like cheating to be honest. I’d come close with the blasphemous blade a couple of times but ended up getting reborn and throwing everything in to intelligence. I’ve gone back in to new game 2 and am definitely going to try and beat her without the magic this time around because although I was happy to finally defeat her I honestly felt a bit deflated doing her dirty like this.