Much too powerful, base stats doing 4k damage+bleed
Im not sure what exactly your going for here, as it looks like it would just be a better murky period, as your biggest poison does more damage than the whole murky, with a bigger radius to boot.
I know that your trying to balance it with a cooldown, but if anything that is a bonus for this poison, as you can only ever throw one at a time, and the main poison is affected by damaging (idk how berserk would affect a poison, unless you mean it ticks up faster) assassins could go purely dps with this poison and just not worry about mp at all. This would make bosses that silence or quite less effective, and an organized group of assassins could insta alot of bosses (a group of 20 assassins could deal 80k damage in one shot if they all used this poison at once)
I see where your idea is coming from, but im not sure that there is any way to balance it with the way you have it without it being an outright better murky, otherwise it would just bust the game.
Perhaps you could mess around with it having an atk modifier for damage and dex modifier for the tick up speed, making it a super customizable poison that can be either a really heavy damage poison, or a really fast acting one, or even just a regular middle of the road poison.
sry for the text wall