There's no denying it was fun to see Rampage finally get back to the win column, despite the somewhat controversial stoppage. Bellator now needs to maximize their investment and be very careful with how they handle Rampage moving forward.
I see no better move at this point than setting up another four-man light heavyweight tournament. Having Rampage contend for the Bellator title would be a big event for the company, which means they need to figure out a way to maximize the chances of Rampage actually securing a tournament victory. That means placing him in a four-man bracket, as opposed to an eight-man field. To maximize their promotional benefit, that also means pitting him against fighters who they can potentially market as stars in the event Rampage stumbles.
With those thoughts in mind, I believe the best game plan here is to pit Rampage vs. King Mo in a tournament quarter final. Mo was an investment for Bellator that hasn't exactly planned out. Matching him with Rampage at least provides some reward to Bellator for that investment. It's a fight MMA fans have been wanting to see for years. While it might not have the buzz to it that it might've had two years ago or so, it's still a big fight for Bellator and can be marketed as such. The other quarter final could be something like Matyushenko vs. Zayats, as both of those men are respectable yet would still be considerable underdogs to either Rampage or Mo. Regardless of the winner, Bellator will have a marketable star on their hands.