For PVE, I use Yellow Moth
P/P a lot as my tamer aquatic pets' killer. I also use Brilliant Kaliri
to finish of any beast of fable with Predatory Strike
(note: this is going to be nerfed hard soon).
For PVP, I guess it will depend on the strategy you're going for. I'll leave it to the more PVP-experienced folks here to post their choices.