I have a theory as to why every Eminem album since MMLP has been sub-par, and why he never hit the potential we saw in Eminem on SSLP, MMLP, and Devils Night. So you know how they did that Real Slim Shady perfomance with all the fake Eminems? I think Eminem paid one of the fake Eminems to take his life for him, and at the end of the performance, the real Marshall Mathers just walked out with the rest of the fake Eminems and was never seen again by the general public.
TES was okay because the new Eminem had lots of guidance, however, members of D12 were really very upset by the replacement of Marshall by the new Eminem. Proof developed an eating disorder, Swifty forgot how to rap, and they were just generally not happy. D12 World was the end of D12, because the new Eminem did not have the talent to carry such an overweight crew of mediocre rappers. Proof was the most shaken by the event, and he gained over 365 pounds. D12 didn't want to alarm their fanbase, so they killed Mr. Porter, and Proof took on the role as Porter while staging his own death, as he was too embarrassed to be known as the fat member of D12.
Eminem (the real Eminem) came back in 2009, so they made up an elaborate story about a drug issue and had the fake Eminem killed. Porter is Eminem's hypeman because he's actually Proof. None of the newest albums have been as good as MMLP because he took NINE YEARS off from rapping to focus on his personal life.
RIP Mr. Porter.