The Testopus Dimension

In Minecraft 1.16.5, something unusual has happened. Stone underneath the mountainous and hilly biomes have been corrupted with a strange new ore... Testium. This Testium ore has strange abilities, such as the ability to be made into some powerful armor, tools, and weapons! And, if you can find a rare item called the Testium Exciter, you can make a portal out of Testium Blocks like a Nether Portal, use the Testium to light it, and go to the source of this strange ore... the dimension called Testopus. In there lies dangers, but also sweet, sweet Testium loot. Watch out for the Corrupted Testopians, and the Corrupted Testopian Brutes, though, they are fast and dangerous! If you are careful, though, then you can master not only the Overworld, the Nether, and the End, but also Testopus!

(P.S. Don't steal the Testium Sorcerer's Ancient Artifact, he's very protective of that!)

First mod, too!