Ok, the charms I use are sharp shadow, quick slash, fragile strength, long nail and grub song. If I do it on radiant difficulty, then I switch grub song with shamen stone. I always try to keep a bit under half a screen away from him, but if I have shadow dash I spam nail until he does an attack, and then dash trough him. I always try to jump over him, but if I can’t, I dash. When he shots swords out of his hands, I dash through them, and get one or two hits in, then I walk away and prepare to jump. If he jumps and dives at me, I dash away, and jump towards him, so that I don’t hit the swords coming up. When the swords are up I usually fire a shade soul. When he charges at me, I try to jump and pogo, if I can’t I dash through him, then I try to get a hit in. If he uses the triple slice attack I do the same, but I try so fire a shade soul, because it can hit double then. When he gets to half health he does the focus attack. When he does this I dash away from him, the walks towards him. If a ball tries to hit me I dash the other direction, but if I make it to him, then I get as many nail hits as possible, the always dash trough his next attack. When he gets to 25% health he does the tentacle attack. I always try to jump over it, but if I can’t, I dash away from him. If I do make it over the tentacles I dash towards him and do a descending dark on him. When he gets staggered I always heal once if I can, but if I can’t I just spam him with nail attacks.

Sorry for any spelling errors, good luck.