I have no idea HOW he got into my underground and CLAIMED but roninpyro managed to get in and will not leave... I want to be able to banish people out of my claim. If someone won't leave, I think we should be able to make them leave.

 

Lava?

 

There are quite a few bugs related to claims.
Sometimes when you want to claim your underground base you claimed the base on the surface of the land.Sometimes the bug happens and the claim on the surface of the land will count blocks above it as claimed and not below

 

i didn't find any broken blocks though... idk...

 

Then he might've been tp'ed into the base