it's a "her"
but yes, that's the point, it's a "super-boss". It's about as bull
as trying to defeat Raid bosses solo in Borderlands 2
"It's supposed to be rewarding when you get past the bull
mechanics!"
I'm going to reference a certain game that does what I'm trying to say has been done by the rest of the mod, and has not been done in that fight.
Dark Souls bosses, for a majority of their existence, are built entirely around the player and their ability to dodge, time and cope with the difficulty they are placed in. Each one of them can be incredibly hard, unforgettably grueling, and getting through their fight in the end usually leaves you with relief rather than joy. However, the thing I personally admire most about these bosses is that (again, a majority of) them do not pull random mechanics out of nowhere that you have never dealt with before, and the mechanics that are introduced for that boss fight alone are still built in such a way that either the environment you fight them in (such as the arena) can help you with defeating them, or there are very evident, telltale signs that such a thing will be used by them. This can lead to players that have never fought the boss before performing in such a way that they can accomplish a victory in their very first attempt.
Terraria, and this mod by extension, is not very different with how bosses are designed. A majority of the bosses in this mod alone are built around allowing the player to understand and deal with the mechanics they find, either because they've experienced them in a less dangerous, calmer setting prior, such as the Devourer's laser portals that are summoned by one of his Sentinels, or they are very obvious in what they change, such as the Devourer's laser walls, or his ability to invert gravity and switch between passive and aggressive modes. These mechanics are built to be very difficult, yet very fair. Several other bosses feature mechanics like these in this mod, and even in the game itself, as the Moon Lord will make it very evident when he's using his phantasmal laser, and he does not direct it onto you the moment he fires it, allowing you to either fail to deal with the set up, or avoid taking damage that will likely kill you instantly, especially in Expert.
And then Supreme Calamitas, with no warning or setup, introduces an unfair mechanic the player has never seen in any boss prior in this mod or the game itself, killing you instantly even if you are able to cope with everything else she's introduced on top of this (an arena of blocks, the bullet hells, the everlasting monstrous moon orb things, Sepulcher itself.) Each and every other mechanic is introduced to you in waves, as the fight literally begins with a bullet hell, and they progressively amp up their difficulty as you progress further into the fight. Even her brothers have been introduced to you before in the first Calamitas fight, making you aware entirely that she will likely summon them in the Supreme Calamitas battle.
Instant death by a hit counter, however... not so much. Do you really have to question why we believe it to be unfair, or out of nowhere? The fact that this thing exists doesn't define it as a super-boss by any standards; tacking on random effects, buffs and mechanics that make the game frustrating doesn't define it as
harder, it just makes it more
frustrating. Difficulty can be achieved by literally any other method than this. And as stated by a user above me, not very long ago...
while it is true that a superboss is supposed to be hard to defeat, there is a difference between real difficulty and fake difficulty. The hitcap (and the instadeath if damage per hit = less than 20) falls into the second category, imo.
Imagine if you've fought all your life with a sword, against people that have also used swords. You're used to them using swords, some bigger, some smaller. But they've always been swords, and you've adapted to this; your entire life has been this.
Supreme Calamitas takes out a shotgun and just shoots you. It isn't hard to beat her, it's just stupid.
