Overview

Hi, I would like to suggest the following:
Scatter three parts of the boss call across the dimensions.
One to the normal world, one to the nether, one to the end.
You could create a different mini dungeon for each part to make it hard to get.

Why would this feature be useful?

I think the boss is very strong and I like it a lot. It would be cool if he became the final minecraft boss, and to summon him, you would have to go through the usual minecraft: Hit the nether, kill the dragon, and so on.
I think it would add to the story, and be very cool.
I hope you like my idea, and that it's not too difficult to implement.