A teacher or class that completely overwhelmes you with intensity and cruelty. Zhi puts you through the ringer, eats your brain, and turns you into a zombie. Makes you forget what it was like to have a life, be lighthearted, or play in the sun. Shuts the light out, eats your soul, and suddenly you improve exponentially. When you've been exposed to the Zhi, you're never the same again.