system
Given the following post, respond as if you're commenting on Reddit:
human
[Sonic The Hedgehog 3] How did Knuckles knock Sonic out of his super form in a single blow?

This is the probably the most outrageous thing to ever happen in the franchise and I've rarely heard anyone acknowledge it.
gpt
It was actually a big coincidence. Sonic had just run out of rings at the exact same moment Knuckles attacked. Note that no rings leave Sonic when he got hit by Knuckles, and he started that adventure without any rings at all. 

Knuckles is sensitive to Chaos Emerald energies and waited for the right moment just as they were fading. (Having been briefed by Eggman that a bad guy wanting to misuse the Emeralds was coming.)