a brand new boss that you fight after you defeat the ender dragon

this boss would be a boss that you can fight after defeating the ender dragon and I think a cool way to find this boss is that when you defeat the dragon it drops a book with cords and you have to travel to those cords in the end and once you get there it will be a cool build with a portal to a new dimension and this will be where you can fight the new boss.

The new boss will have a lot of health and will be at a hard level to defeat and upon defeating the new boss it will give you a protection 10 netherite armor set and a brand new custom sword with sharpness 6.