The key to the corrupted nether is not the nethermen, but rather the wither himself. The wither is bound to a withering island. You must find the necessary materials to find a reactor. From here, you need to build a portal in the shape of an end-portal made of basalt. Once done, you can place the reactor in the very center of it. That will make a portal to the withering island. (the dimension may be janky)

He will drop the needed items to get to the corrupted nether. He drops nether pearls that can make the core to gain the nether frames. This portal will lead you to the nether dragon.

The dragon's defeat will mean you have completed the addon. Afterward, you can explore the creatures and plains of the corrupted nether. There will be random treasures and foliations of the dimension to explore. Beware the creatures of the realm.

Withering plains.

Ice-fields. 

In the overworld, you will see the sky world.

The rest of the addon is a mystery.

As well as coming with its own combat system:

All I can ask is to be careful and discover what you can. There are optional bosses and custom weapons to find.

V5:
The dodge mechanic was altered for the sake of mobile players and console players. You must look down, jump, move in any direction, and attack. This will make you dodge in the direction you are moving in.

There is now a ton more content to see.

You must now activate the corrupted nether portal with a new reactor and design.

There is a new dimension apart from the Withering Island called the Old Void.

There is 6 new bosses to find, 3 of them to be constructed.
 

Most bugs were fixed, and this edition was optimized for 1.19+ and lower end devices. There are also cutscenes now.

There are 11 new armors and ores, along with new weapons. All structures were changed and altered, and the CN has a ton less Malik.

Stay weary, and check out the video for this addon: