User blog comment:SilverHexxitFights/Which is Terraria's Hardest Boss?/@comment-7842889-20131113030345/@comment-1466854-20131113053941

Strong armor with vampire knives seems to only fall short on Paladin and Pumpkings, assuming no significant dodging (including hammering Paladin from above while grappled). Maybe Mourning Wood too, but they're so easy to dodge I never really take damage from them until the obscene massacre that is wave 15. Generally when considering boss difficulty, I consider it by which ones are hardest to finish off quickly with minimal loss of life, relying on skill instead of cheap tricks to survive. Not that I mind cheap tricks of course, but they're not really a fair consideration in this case.