Xenin is the strongest member of the Dark Legion as he was "rebuilt" to be able to withstand Knuckles' attacks--which he can. He's "more than an echidna" and completely ruthless as he doesn't care whether he kills anyone who stands in his way or not. He just follows his orders and has "fun" beating or threatening others. He also tells really dumb jokes.

If the image didn't tell you this group parodies the Marvel series X-men. Such parodies are ridiculously common in the Fleeway one off stories.

The group consisted of Cycleclips (“Team leader”), Grey Jeans (“Wild but well-groomed”), Armpit (“Hold your noses”), Chimpoline (“The angry ape”) and Snow Monkey (“Chimp of chill”) and were lead by Professor Zed. However, it turned out they were more posers instead of heroes and the villains always managed to escape them thanks to “Hero Hour”, a time where their professor told them to stand in heroic poses for an hour. Sonic suspected something was up about this and discovered that Professor Zed was actually the Zed Monkey’s enemy Madmeano. Even after his defeat the Zed Monkeys didn’t learn from their experience and changed Hero Hour to Agony Hour, in which they stood around for an hour feeling sorry for themselves instead. Sonic decided it was best to leave them to their games.