When Death is released from bondage, loosed from the Devil's short leash, the first thing he does is eat another deep-dish Chicago pizza. It doesn't taste like freedom, exactly, or victory, but it is enjoyable in its own way.
The next thing he does is to reestablish his command over the Reapers. A brief show of force - several sudden, inexplicable deaths - is all it takes to confirm for them that he is who he claims to be.
The third thing he does is find the others. The rebels, the cowards, the bored and the curious. Those who challenged in his absence, or ran, or wandered. Most of them return willingly enough, with a few notable exceptions.
Death allows a number of them to continue playing with the odd little disc-world they found; some independence can't hurt. And as for the Reaper who's taken to following Dean Winchester around... well, he supposes that to a Reaper the boy might be of some interest, so he leaves her be.
But, as for the other Reaper to take interest in a human...
"Ryuk," Death says. "That's enough. Give it to me."
The Reaper tries to protest. A mistake.