Containment chamber

A containment chamber was a technological structure used to keep a conscious, powerful being imprisoned for extended periods of time. It consisted of a large stake-like structure to which the prisoner was shackled, standing, as well as a square base which projected an invisible, cubic forcefield around the stake.

The Division imprisoned Swarm in a containment chamber which remained functional for millennia, being checked in on every thousand years by Division agents. Eventually, however, it broke down; Swarm took his opportunity when the power shorted out to kill En Sentac, fueling a regeneration. In his new, stronger form, he effortlessly broke out of his shackles and escaped. (TV: The Halloween Apocalypse)