Poison has a very long lasting DoT that does low damage per tick, but totals up to be over double the damage in a single hit. (5% of the attack’s damage for 19 ticks) That seems to be very good on paper, and it is extremely powerful against NPCs, but against players, it’s fairly weak.
Poisoned effects don’t stack, meaning a lot of your hits will not actually do anything other than the (relatively low) base damage and the poison cloud damage, and because the poisoned effect lasts so long, this will happen for a lot of your hits.
The poisoned effect itself isn’t too good against players either. It does so little damage that players can outheal it. A level 60 poison user without a power set will do about 3 damage per tick, and a player can easily outheal that. At most, it will negate the enemy’s health regeneration, which isn’t actually as good as you would think it would be, since poison clouds are easy to escape and the actual hits don’t do too much damage either. (especially compared to some magics like fire)
I feel like either the poison effect should stack a bit, making multi-projectile moves more useful or the poisoned effect should negate regen. Right now, you pretty much cannot kill a player using the poison effect unless they are a much lower level than you. Granted, if anything like this got added, it would probably mean a nerf to it’s base damage, and probably the clouds too, but I feel like this would also help distinguish it from other elements with DoT like melting, burning or scorched. Thoughts?