Hardest Boss you've made?

Essentially, I made a boss that transforms into more difficult forms, with cutscenes between each form. The final form was actually the smallest form but had auto-regen 100% life per tic and mega high defense, but average attack. It had no magical attacks or defenses except for auto-regen. (Which like I just said, heals him 100% the life every tic). The auto-regen lasted 6 turns then the boss would recast it. The only way to win was to cast Silence on him, but he was immune to all magic attacks, so you had to use items that silenced him. He had a lot of life and defense, it was difficult because it was more like 'how long can you keep on punching a brick wall' + 'how many of those silence items do you have left' kind of thing.

I gotta do that last part in a test just for shits and giggles. Sounds like a blast.

wall punching minigame?

The hardest I think I've ever made was a secret boss in the ABS game "Anima". Namkcor had to tone him down in difficulty in the final version, but before then, he was an absolute bitch to kill. At first it would seem like an easy battle, but soon it would roll into an intense 10 minutes of spam healing and attacking like crazy, and this was just on easy mode alone. Stat-wise, he mostly matched the final boss save for having nearly double the number of health points, but where his difficulty came in was his attacks. He launched a powerful explosive ball of energy that would home in on you if you got close enough, and would then teleport away to mess up your ranged attacks. The only way to defeat him was to use a DEF UP skill, ATT UP skill, get in close and nail him as many times as you could before your health got about halfway down, then run away and heal yourself up as best as you can, waiting for your SP to replentish and heal yourself from the damage you took while waiting. Rinse lather repeat, with him becoming more aggressive and teleporting more often to get away from you as his health got lower.

yeah I had to tone him down, I mean seriously
homing missiles that hit you for like a quarter of your health every time
and no cover to hide behind :|

I like the final version with the portals though

Kane. Anyone that followed Clericus should know who that is.
You were to fight him fairly early in the game, and unless you'd done an excessive amount of level grinding, half his attacks were likely to KO your entire party in the first round, and he would evade every other attack.
I did a shitload of battle testing with the RTAB, and it took me many, many attempts.
Then when I later tried to implement the TBS, his range of movement was ridiculous, and he could target multiple characters in a line like the laser eyes in Shining Force.

I think bosses that are just straight up over powered are dumb. They're there to be nothing but a nuisance and make the player angry. There's not strategy for it except to grind your ass off then face them again on your own terms. If there's an actual strategy other than being 20 levels higher than the boss, then I'd say it's a good fight. Or, if the boss was lvl 1 and you're level 99 and the boss is still difficult by means other than shear power. Strategy and thinking is what's fun.

Essentially, I made a boss that transforms into more difficult forms, with cutscenes between each form. The final form was actually the smallest form but had auto-regen 100% life per tic and mega high defense, but average attack. It had no magical attacks or defenses except for auto-regen. (Which like I just said, heals him 100% the life every tic). The auto-regen lasted 6 turns then the boss would recast it. The only way to win was to cast Silence on him, but he was immune to all magic attacks, so you had to use items that silenced him. He had a lot of life and defense, it was difficult because it was more like 'how long can you keep on punching a brick wall' + 'how many of those silence items do you have left' kind of thing.

I gotta do that last part in a test just for shits and giggles. Sounds like a blast.

I forgot to mention that he was immune to all other status afflictions other than that item silence. That was the point of him to have no magical attacks. His casting of auto-regen wasn't really like a magic attack it was like some stupid plot item that the boss had that he could use in battle, which is why it was dependent on items to silence it.

It had 5000 HP and leet skills.

End of story.

I don't make games, but I remember the toughest bosses in RPG maker games are usually the first ones. You aren't use to the battle systems, your characters barely have any spells. That says it all.

It was the boss that had a thing for the main character

he was like "yo i got a buck i heard that was your going rate"

then the MC was like "Ebichu raised his rates, a ho like me needs to get the best dollar now Megaman!"

then Megaman was like "the hell I don't need this bull while I'm running for mayor"

then the battle it was like the boss he had 3 turn move

it dropped a 360 on you then you died

... and now I'm missing Phil

Anyways, I guess if I reply I may as well be relevant t subject at hand hardest boss? Well a game idea that is in the works called "NPC" has a secret boss, the protagonists.

Basically 3 spiky haired 16 year olds who are incredibly overpowered (since the point of the game is that your an average NPC who is board of having no purpose in live but to give advice to PCs you are underpowered, to say the least).

One is the basic blond fighter guy with high speed and attack and some healing magic.
Another is the guy built like a giant with dark, short spiky hair who has incredible DEF/ATK
Third is the female mage who has disgustingly low ATK/DEF but can use every spell in the game.
They also have 99 potions, 99 eithers, and 20 phoenix downs.