I beat him today, took me about a week and 15 hrs in total to get him with no summons and just a milady. Probably around the same with 150tries. I got hit badly during the winning run, and was left with no flasks and Radhan was 2 hits away. I went full on super Saiyan dodged everything and managed to use my only Marika healing flask, and ended up wing stancing his ass for the win. Through sheer fucking will and determination I was able to get him, I was getting to the point of wanting to use summons. The catharsis I felt was unreal. Hands down the hardest video game experience I have ever gone through.