A Knuckles you don't want to mess with
Without a doubt, Knuckles is one of the biggest parts of Sonic the Hedgehog 2. Much of the film revolves around Knuckles, who he is, and what his goals are. It’s a considerably serious take on Knuckles, which is something we haven’t seen in Sonic media for quite some time.
In an interview with Polygon, Sonic the Hedgehog 2 director Jeff Fowler opened up about the film’s portrayal of Knuckles, and why it was important to go with a more serious tone.
I think it was really important that the movie and the story took him seriously and [Knuckles] certainly has been played for comedy at his own expense a lot of the time. So while we still love that idea, I just wanted to double down on the threats [Sonic] is facing. Obviously Robotnik is always there, and is always going to be challenging for [Sonic] and that’s his sort of true arch nemesis. But we wanted to pile on another problem for Sonic and to throw Knuckles into the mix, and have him be very formidable as an opponent. Sonic loses most of the fights against Knuckles in the movie — [Sonic] doesn’t win any of them, right? And that’s because Knuckles has spent his whole life training for this mission and this purpose. He’s got this legacy. He’s the last of the echidnas and his whole whole purpose is to honor the legacy of the tribe and do what they could not do. So that was all very dramatic. And it felt very cool for a Sonic film to really treat Knuckles with a lot of respect, and just make him a badass.