New end mini boss

So, I was wondering if you can make a mini boss in the end, like she's in the palace in the middle of the void and make her humming so nearby players will notice her and find her spot, and if the player got to the structure, the boss will spawn a 4 musicians carrying a 4 instruments like piano, violin, and etc. There propose is to give an negative effects to a players (i will leave the instruments to youll) and to defeat them is they have to fight the one that giving the negative effects and if they managed to kill them they will get the instruments and use the same effect while using it to other players or mobs, and back to the mini boss, if the boss summoned the musicians she will now charge a star like lining energy ball and if she released it the players that managed to got hit by this will get an effect of the mini boss that if it get stacked to full, the next time you will hit by one will explode and will break your armor fast, and in the half health of the mini boss she will eventually going to last dance which is she will spin slowly to rapidly as she goes up and while she doing this she will release a particle that will damage you through your armor, and if the player managed to defeat it it will drop her core which can be craft mystic items. I suggest this because the end is literally nothing if you managed to get the dragon and the elytra, I mean is I want to the end become lively and mystic items that will comin handy and clutching moment for minecraft experience.