I hardly see any need for poison to be buffed. Poison is a completely legitimate way of fighting - amongst other things - the Eternal Guardian. It provides a considerable damage boost against tougher opponents. Not even Fistanarius can boast an immunity. Basically the only thing that makes poison useless is either a complete inability to hit opponents to begin with, or damage output high enough to dispatch them before the poison gets to deal a considerable amount of damage. Often the latter, as regular monsters seldom merit the usage of limited resources of any kind.

In later game you normally can damage anything pretty well. If you can't hardy poison is a solution. If it is a solution it is helpful only a few possible scenaros. Normally any class can afford enough poison at this stage.

Therefore assasins ain't really unique and doesn't want to use poison much more than any other class.

I support it. Assasins need some favor.

Poison is pretty OP in some way *spoilers*