Erick Stevens
I'd bring him in as an enforcer for Miz while Miz is feuding with Bryan Danielson. The first month you'd just see him assaulting Bryan and helping Miz get wins over him. Then, at the PPV the Miz Show lose the titles (because of Bryan). Show abandons Miz and decides he's done tag teaming and sets his sights on the WWE World Title.
Miz and Stevens form a tag team in the attempt to recapture the Tag Titles from whomever, with Bryan interfering and preventing them from winning the gold. This sets Stevens up for a fued with Miz whom he blames for their lack of success. This leads to a match between Bryan and Miz for the US Title at the next PPV. Miz loses because of Stevens turning on him. Bryan moves on with the title, Miz feuds with Stevens for the next month culminating in a PPV Last Man Standing match where Stevens dominates the Miz.
Next Stevens starts a feud with R-Truth with every encounter ending with Stevens hitting the Doctor Bomb (his finisher) on Truth. The reason for his ruthless attitude is explained as a result of the grueling and mentally scarring Last Man Standing Match from the prior PPV with Miz. At the next PPV Stevens has another Last Man Standing match with R-Truth whom he defeats in another brutal (not bloody though, WWE's pg) bout.
The show directly after the PPV has a the special guest host put the World Title on the line against a mystery opponent. (For shits and giggles it's either Swagger or Sheamus) During the match Stevens hits his alternate finisher which is a reverse piledriver and gets the cover for the win. As he's celebrating the crowd is informed that the match must be restarted as his finisher is considered "illegal". As the match is restarted Stevens is taken by surprise by the Champ who wins with a school boy (using the tights). The next episodes before the PPV show Stevens in an uncontrollable rage going around and hitting his piledriver on random mid-card faces. This peaks Randy Orton's interest. He challenges Stevens to a "No Holds Barred" match at the next PPV and he accepts. Randy Orton takes the win after 20+ minutes in the ring, a blatant attempt to get the fans behind Stevens.
The next show they push Stevens as tough as shit because he kicked out of two RKOs and only went down from a punt to a steel-chair he was bringing into the ring. He comes out and cuts a promo about how he respects Orton and this is when Bryan Danielson the US Title holder comes out in full heel-mode. The two insult eachother and Stevens challenges Danielson for the title that night in his "favorite match" (Last Man Standing), Bryan accepts for the Main Event. Bryan retains via interference from the Miz.
Enter John Morrison. From this point over the next few PPVs until the last before Mania, you have Morrison and Stevens VS. Miz and Bryan for the Tag titles.
PPV before Mania, Miz and Bryan lose the tag titles to Rey Mysterio and John Cena.
Wrestlemania it's Miz VS. Morrison and Bryan VS. Stevens in a 30 Minute Ironman match which sees Stevens take the US Title as a face from the heel Bryan.