"Deuce" is the highest level player in Halo 4's multiplayer. Deuce, who goes by "hugedeuce" (possibly implying that he's a big piece of Doritos-flavored, and Mtn. Dew-colored poop) achieved the Spartan Rank of 130, making him the highest level player in the world. As the highest level player in the game, Deuce also maxed out each specialization.
He posted a picture of his accomplishment on IMGUR, which you can see below, which he captioned "Looks like Kal'Reegar was reborn as a Spartan", a reference to the quarian warrior in Mass Effect 3 voiced by Adam Baldwin.
He held a small AMA interview session with other players on Reddit's r/halo board, which you can read here. He gave some choice answers to players who asked him what he was going to do next, seeing as how 130 is the max level in Halo 4.
"Not a dumb question," he wrote. "I still don't know the answer haha. SR130 is the max until now until 343 decides what to DLC some more specializations. For now, i'm working on 100% commendation completion."
He also explained that there's a daily XP cap to prevent players from grinding non-stop, which is something not many people know about. Interesting.
Most of the questions on the thread complain about the lack of multiplayer maps in Halo 4's War Games, which is a complaint that 343 Industries will hopefully address in upcoming DLC releases for the game. It's enjoyable to be sure, but there's only so much fun you can have with the same small set of maps. Thankfully, the game offers a wide variety of different modes, so it doesn't get stale too quickly.
Anyway, congratulations Deuce!