I feel, 1v1, the better duel is with Champion Gundyr. Especially NG+ where I think he's given the right amount of health to shine. When you're out of Estus and the song kicks into the horror movie sequence with the violins, screaming "you're going to die now" and you're dodging everything like Neo, and you don't even know how, and WTF, WTF oh god... yeah, I love that fight. Gael has some of that. Ironically, more in his first phase where he's more dynamic and Gundyr like. After that he goes straight into basic patterns. But he is quite the show.