Brock Lesnar returns to Raw and attacks John Cena.

Brock Lesnar's shocking return on Raw SuperShow generated a wide range of reactions from the Miami crowd. Some members of the WWE Universe chanted his name and imitated his signature entrance motions. Others dropped their jaws and were in complete and utter shock. ( PHOTOS)

Brock's back, baby. And he's left some huge questions to answer.

For starters: Why is he back in WWE? Why has he targeted John Cena?

The leader of the Cenation had invited The Rock out to the ring at the close of Raw, not looking to pick another fight but to congratulate him for his victory at WrestleMania XXVIII. Before he could even get a response from The Great One, Lesnar's music reverberated throughout the AmericanAirlines Arena. In one venomous instant, Brock turned a handshake offering into a devastating F-5 that immediately changed the entire landscape of WWE.

Lesnar, a three-time WWE Champion, hadn't entered a WWE ring since WrestleMania XX on March 14, 2004. Now, eight years later, he came back to brutalize one of WWE's most legendary Superstars, a man who was already coming off an agonizingly close defeat on The Grandest Stage of Them All.

What kind of message is Brock trying to send Cena – and the entire WWE Universe – by punishing the Cenation leader? We can only speculate at this point, but there's no denying these two have a heated and tumultuous history. In early 2003, when Cena was first trying to climb the Superstar ranks, he sought Lesnar's WWE Championship and even mocked his finishing maneuver – the very move that crushed him on Monday night.

Is Lesnar back to prove a point to Cena? Or is he just on an uncontrollable rampage?

Only one thing seems certain right now: Brock Lesnar has rocked WWE once again … and he sure looks hungry for pain.