Board Thread:General Discussion v2.0/@comment-26347196-20151109173852/@comment-28737464-20171119035552

Akkaviv wrote: Wikipedian nobro wrote: Sans is FAR BY the hardest boss, at least the second half of the battle. I don't get why some people think that Asriel or Flowey is harder. I agree...

But some people argue that when you memorise sans's attacks, they become very easy to remember. That means that when you "kill" him and try to fight him again, it will be a lot easier than the first time.

Its pretty hard to memorise asriel's or flowey attacks. They are random and chaotic. Well, at least for the first time you fight them.

BTW, I think Asriel is the hardest for no-hit.