This guide will help you with 100%. I will not be covering armor that you can get.
Guide to Find and Defeat Hidden Boss
How to Find
First you need to find the card in each respective starting area.
The castle space place and the school place (you do not have to equip them to use there card effect on the overworld).
This can take some time but doing this guide can help you beat the game. Not like games hard its just a fun easter egg.
From my knowledge it was the original (spoilers!) but didnt make it due to not fitting the games serious approach.
Anyways after you get the cards you need sleepy tea. Which is obtained in the west wing of the 2nd area (mansion area).
You will have to find a safe and hack it by completing a tiny maze. You will be notified of the minotaurs approach by dialogue.
I recommend to leave that room and look in every direction before choosing. i think you have 3 chances.
Spamming works but its unlikely that you win that way. You can also choose to memorize everything to get the least amount of strikes.
Once it is hacked head on back to the two bats talking about sleeping (there the ones near the bedroom).
Once you give it to them you are able to proceed. This is where the final boss lays. Once you use your cards and make it to the final area you need to go.
You need to go through walls. The puzzle is not at all hard as it only consists of one path. This is where the final boss is.
Note: make sure to save your game incase you lose.
Hidden Boss Fight Strategy
The boss isnt hard.
This boss’s gimic is that they attack with those oh so annoying clock effects. Low damage but hell can you get overwhelmed.
2 words: timstone ether. These two things work like magic for laziness.
Simply spam the hell out of tim stone and replace it if you can. Use the useless characters like christ or finley to make sure his tp doesnt run out.
If you doing a run just for this boss upgrade only tp when you lvl up. It helps a bit.
Your main source is going to be dharts (try to enjoy him while he lasts) spam timstone and lil help. Timstone tanks damage very well as her.
Timstone works as they deal 1 damage per attack. But be prepared if it breaks cause if it does there angel wing thing attack with the music notes will attack other people once it breaks.
Speaking of attacks. She attacks with… summoning a 1 hittable but spiked music note. Flying in the air but faking you out by throwing there wings at you and forcing you to dance (wasd controls). I died to this but i think you have to just dodge the attacks by “dancing” away from there lasers. They also fly up in the air just like any other boss besides the rose.
Sometimes they attack with barraging flying notes that are tricky to hit a dodge on. They attack 2 random allies so once you got whos getting hit by what (hoping you didnt get clocked and no longer can block/dodge) it becomes easier to dodge.
The final attack is the most common and the most easiest to deal with. Its hard to tell whos getting hit if theres 2 members in a lane but play it safe and you can get done with it. If someone dies including timstone it will keep attacking the timstone. Your main source of damage is damien. Always use witty line and make sure that theres no sharp note. Get rid of it with finley or christy but not dharts.
Note: you dont need potions cause u got a frick ton of ether and a heal from finley.