Feta Mode

When someone does something terribly; someone falls apart

He went into total feta mode during that game
i.e. he did not play well

Juggernaut-mode

When you are so overworked that you no longer feel pain, exhaustion, or anything. Your brain is essentially on auto-pilot and you just keep working.

The bossman has been here since yesterday morning. He even burned his hand on the fryer without noticing. He’s on Juggernaut-mode right now.

Dude you literally walked through and knocked down an entire display shelf.
Sorry, I didn’t notice. I’m on Juggernaut-mode right now.