system
Given the following post, respond as if you're commenting on Reddit:
human
[40k] What's stopping anyone from attacking/destroying Terra to kill the Emperor?

What's stopping any race from launching an assault to kill the emperor on Terra?  I realize it's probably insanely well defended, but with so many forces widespread, surely some race could launch a direct assault, or use some sort of weapon to destroy the palace/planet he resides in?
gpt
It's *literally* the best protected planet in the galaxy. There is an army of Custodes who would most likely flip shit if you got near, and the Lords of Terra will *not* risk their livelihood. This isn't invading the White House. This is invading a Vatican stuffed to the gills with super soldiers and ridiculous defense grids, populated by Super-Jesus President.