Ah yes. Knuckles the Knuckles and Knuckles.
Perhaps I should give a brief history and Knuckles.
Born on Angel Island, he lived alone for many years as the protector of the Master Emerald. One day he was found by Dr. Eggman, who tricked him into thinking Sonic was attempting to steal it (Oh no!). So Knuckes beat Sonic out of his Super form with his bare hands and then set traps everywhere while chuckling at every turn. But Sonic kicked his butt, and that's why Knuckles doesn't chuckle no more.
Knuckles is also the last Knuckles because all the other Knuckles killed helpless pets because they were jerks and ticked off a mutant angry pet, except for a girl Knuckles that managed to hold it back because Knuckles. But Eggman did a thing again so Knuckles had to go help deal with it.
Nowdays Knuckles just does whatever because it's obvious he's not getting his job done anyway. He keeps the Master Emerald in a pile of magical enchiladas because it's a ward against mad scientists and Rouge thinks it smells too bad to go near it.