Guild Wars 2

Which Sigil would be considered better?
The 10% durration from Agony or the +10 per kill from Corruption?
I am strictly PvE and I run a 20/30/20/0/0 build, standard useing Scepter / Dagger & Staff ~ BiP, Epidemic, Utility and Elite (changes with situations).

P.S. Talking about Offhand for Dagger~

Scepter of earth, Dagger of agony, Staff of corruption – assuming your build

Build corruption stacks during the first trash packs/non elite packs

If you are a PVE DPS spec I would advise making your 3rd utility worm/shade and running 30% pet dps in spite, pairing this with flesh