Teraphobia (New dimensions addon, 1.21.30+)

This addon adds 200+ items, 100+ mobs, 40+ bosses, 5 main bosses and 3 dimensions.

I got the creator's permission so do not report:

Teraphobic Realm gives you a tiny glance into Hell, showing the adventure you make for yourself is only monstrous because of you. You are a player in a world of monsters, and it is up to you what you will do about it.

When spawning in, you will be given a guidebook that explains most of what must be done to get the proper experience. Feedback on this experience is desired. You will also be given an item that lets you toggle the dodge mechanic, a mechanic that will cause you to dodge in the direction you move in when you press the sneak button, swiftly dashing you and giving you resistance MAX for a split second. This is to compensate for the fact that all mobs with melee attacks have been given delayed attacks, including vanilla mobs.

This addon will hopefully give you a different way of playing or thinking about Minecraft, allowing you to develop your playstyle as you go on.

If you think the dimensions are like they used to be, that being boring boxes in the end with unstable generation, think again.

There has been a change so the addon is now back to its former hype under its original name: Teraphobia.

For an idea of scale: 3 new dimensions, and that barely scratches the surface. The guide you spawn with will help you.