Help @ Corrupter Of Worlds

So I was at the phase of the quest "Temple of Legends" where you have to go kill the Corrupter of Worlds, and I got stuck (literally) on one part, where right before you go to the Corrupter and he destroys the floor below you to a black box that teleports you, and there was one block that wasn't destroyed, so I stepped on it by accident to see what happens, and now I'm stuck lmao anyone want to come help?

 

/kill bro.