Cleon
Legend
Going in reverse order:
I'd agree with keeping only penalties in the table and allowing the DM or player to decide on what description to use.
I do like bonus empowerment points as the benefit for the sin-eater. I don't know if they need restrictions (especially use against evil creatures, since the original text specifies that sin-eaters can be any alignment); the afflictions are probably enough of a penalty.
Okay, let's aim for bonus empowerment points for the time being.
The questions to address are then (a) how many empowerment points, and (b) how does this affect the "An ovinaur may never have more empowerment points than 5 times its Hit Dice" in its current Discerp draft?
For the second, I suggest the following simple addition would address the issue:
An ovinaur may never have more empowerment points from discerping than 5 times its Hit Dice. Ovinaurs can gain additional empowerment points using their sin eating ability (see below).
Or possibly:
The maximum number of empowerment points an ovinaur can gain from discerping is equal to 5 times its Hit Dice. Ovinaurs can gain additional empowerment points using their sin eating ability (see below).
As for plot-relevance, you give a good example of the use of sin-eating on an NPC since it prevents return as an undead. If you want to add something else, what if it provides the effects of gentle repose or something?
I don't care for gentle repose, but was thinking more of remove curse or break enchantment like effects.