how did the vile get into under realm invincible

The Vile got into the Under Realm because they were forced there as prisoners , not because they naturally belonged there. In Invincible lore, Satan and his demons trapped the Vile below after a violent power struggle, and the demons’ role became guarding them so they couldn’t return to Earth.

Quick Scoop

• The Vile were described as ancient, powerful beings tied to the Under Realm’s history.

• They were imprisoned there by Satan and demon forces to stop them from reaching the surface.

• A recent episode framed it as a long-running containment effort: the underworld’s job is less “rule the dead” and more “keep the Vile locked away”.

What that means

The short version is: they didn’t “get in” by accident — they were put there on purpose.

If you mean the newest episode specifically, the story says the demons are basically jailers, and Volcanikka/Vile-related conflict is about trying to break that prison system open.

In one line

They’re in the Under Realm because Satan’s side trapped them there after defeating them , and the demons have been holding the line ever since.

If you want, I can also explain who Volcanikka is and how she connects to the Vile.