He is a demigod of destruction in the domain of death, but that does not mean he is cold or even unkind. Pelegath is a fatherly deity that gives generously and asks little (think Nurgle without the space AIDS). His role may be destructive, but he is by no means chaotic being and very much cares for the natural order of the universe.
He is not usually malicious toward other deities, but he does tend to distance himself from other gods in favor of the company of mortals. This is not to say he will not lend aid if another deity calls on him. Save for actions that would spread the corruption of necromancy and acts of needless destruction, Pelegath is always willing to lend what aid he can.
The Lord of Rot is comparatively easy to appease with only two things are needed to gain his favor. The first is to erect a small shrine dedicated to him. With what and where the shrine is constructed are of little concern, it need only be a place where offerings can be made. The second requirement is that offerings are to be placed on the shrine and allowed to rot without interference. Such offerings may be a piece from a hunter's kill or a portion of a farmer's crop, anything that can rot. The act of offering means more to him than what is being offered. Especially devout followers may give themselves at the end of their lives and allow their bodies to rot on one of his shrines