if you unironically think undyne the undying is harder than sans please let me know in the replies so i can laugh at you
its true, sans is really easy and undyne is just not as easy
Sans is only a matter of memorizing his attacks, there are plently of people who can vouch that undyne the undying is harder
solo spamton?
Also I found Chaos King harder than Giga Queen
undyne has 2 random attacks while sans has 4 though?
undyne’s pattern is also completely consistent
sans has way more rng than undyne, one of undyne’s rng attacks is also her easiest while sans’ random attacks are his hardest
Frankly, I find sans’ heal attacks rather easy
undyne has 2 hard attacks in the entire fight though and none of them are as hard as most of sans’
solo spamton imo is equal to jevil or slightly higher, spamton’s attacks are still way easier than jevils even if you lose 2 turns
they’re both pretty easy but i think giga queen is harder
ok i just recorded an undyne the undying fight can you tell me which attack is harder than sans
keep in mind it was very scuffed and shitty
Mettaton Neo is harder than all of them combined.
i feel like this tierlist is missing a few bosses
wait yeah, where’s napstablook or mad dummy
yeah i completely forgot mad dummy existed im ngl but it would be in medium
napstablook would be in easiest
normal spamton too
(this one)
that shit barely counts as a boss imo but if it had to be ranked then easiest
ill try to give an in depth explanation for every boss on this list
zenith martlet: this shit borders on unfair
sans: the hardest enemy in normal undertale, he is essentially impossible to beat without full memorization of his attacks (which hit like fucking trucks) and even with full memorization, can still be fucked up due to his hardest attacks being rng related
genocide ceroba: this shit borders on unfair x2
undyne the undying: she’s hard but not quite as hard as the ones above her, her attacks are always the same like sans’ but not as difficult as his. You might (and probably have on your first playthrough) beaten her without full memorization of her attacks, this is also my theory as to why people keep saying shes harder than sans when she just objectively isnt
jevil: he hits like a truck with completely random (and hard to dodge) attacks, although not even remotely close to sans or undyne in terms of difficulty
genocide axis: he has hard to dodge attacks that deal a lot of damage that makes him hard idk what to say besides “now i know that sounds bad”
flowey (undertale yellow): this is basically omega flowey if his attacks were difficult to dodge and dying undid the soul phases, his first phase is extremely easy due to the endure and hope acts but the second phase is why hes this high
mettaton ex: at least on pacifist his attacks can be challenging to dodge, nothing too crazy though
muffet: the undertale difficulty spike, idk why shes just that much harder than any of the bosses fought before her but she is
asgore: attacks are somewhat hard to dodge idk what else to say
spamton neo: probably the hardest one in the challenging category but still not even close to as hard as anyone in the pretty hard category (except for snowgrave spamton hes = to jevil)
genocide martlet (snowdin fight): she’s hard to dodge and deals damage idk
pacifist/neutral axis: the soul mode is difficult to work for me at least, he also 4 taps you unless you have the golden bandana so thats not great
pacifist ceroba: a lot of people complain about this boss but she’s not as hard as axis, her attacks are somewhat random but not that difficult to dodge, and if you die you respawn in the same phase you died in. you also get free healing acts so items arent even that important
undyne neutral: she’s not that hard, but is a difficulty spike from papyrus and toriel
omega flowey: this one would’ve been hard if not for the fact that you cant die in any of the soul modes and if you die outside of the soul modes they remain greyed out
asriel: he does a lot of damage but you dont really die to him you just go back 2 turns, he also has the hardest attack in the game to dodge which is cool i guess
giga queen: like most here shes not that hard, just harder than the ones below her
neutral martlet: she does a decent amount of damage but her attacks arent
very difficult to dodge
mad dummy: not that difficult but not easy compared to what came before
guardener: she has somewhat difficult attacks but doesnt deal much damage
papyrus: you cant die
king: spam dual heal and you cant die
berdly: easy to dodge
queen: spam dual heal and you cant die
dalv: easy to dodge
starlo: easy to dodge
toriel: you cant die
napstablook: easy to dodge
spamton normal: easy to dodge
kround: easy to dodge
rouxls kaard: you can literally end the fight in 2 turns lmfao if you can dodge a single attack you can no hit it
Next tier list should be based on style points
mettaton sweeps everyone else in z tier
why the HELL is rouxls kaard in the easy tier??? he’s the greatest puzzlemaster evah… I got stuck on him for 4 weeks trying to solve only his first dastardly creation 
The random encounters in yellow are harder than his boss fight