equip a dagger, as stated in the skill
and its not just all about damage
afaik conviction lowers the poison res of enemies here, ontop you can use lowerres aswell, and -res on gear, so you might end up with mighty psn damage there already
100k would be 462 damage per frame, that'd be quite noice
imo the maelstorm is 2x better than poison nova, you can use it from a secure distance, and it does more damage per second, but it works with ias, not fcr
its like a ninja skill sort of... or mortal combat style
to sum it up, you can even easily break psn immunes
the most trashy element ingame is still fire pvm :/ although its new skill is kind of cute