Board Thread:General Discussion v2.0/@comment-26347196-20151109173852/@comment-25398349-20180118173947

Assuming we're only talking about final bosses? I can only base these on my current experiences (as in first experiences with the boss)

Photoshop Flowey - Majority of it is the shock of Flowey. Though I will admit, his attacks are a struggle at times, he’s definitely given me a few resets. Asriel - I think I may have died one of two more times during this fight. Wait... I didn’t die! You literally can’t in this battle, not to mention you can literally just get free healing items. Sans - Even knowing how bad of a time I was having going into this fight, Sans has done at least triple of what the other bosses did to me. However once you know Sans' attacks well enough, he’d be the easier fight of them all. So it really all depends on the skill/practice.