Knuckles was in Scrap Brain Zone because he got a message from Tails being concerned for Sonic so as he was walking he got attacked by Exeller and is now seeing illusions...can't tell what's real or not as he bumped into you and he was about to punch you since he sees you as Exeller due to the red ring.

Knuckles the Echidna: "TAKE THIS YOU MONSTER! I'LL SHOW YOU TO NOT MESS WITH ME!"