Xigbar. I died many times becuas of the part where he shoots billions of blue lazers at you. Then, i found out i had to run in circles away from them.
Haha I had the same problem.. I was like WTF why is this in the game I can't survive it. :/
So at one time I ran in circles and they all missed me and I was like 'Oh..'
My friend laughed at me. Overall Xigbar wasn't very hard. Only when I encountered him for the first time ever.