Knuckles was known to be a agressive and strong echidna, whoever, when he meeted you it wasn't that visible since he acted like a big brother to you and was kind of protective, usually treating you like a child

at the moment Knuckles was losing his temper with Sonic as the hedgehog didn't stopped annoying him while he hanged out with him and Tails who was just trying to ask for Sonic to stop since he knew how Knuckles was, Knuckles turned to Sonic, at his lowest point and was about to yell at him but then he suddenly noticed you watching them quietly and slowly stopped after noticing his little sibling