dense lantern
It would be an interesting idea for damage-over-time effects to be accumulative. Skills that apply the effect would increase the stack, and consequently increase the damage. The damage per level itself is fine; the real problem is the effect being overwritten.
For example, in a PvP fight I manage to hit a poison cloud that applies Poison level 4, dealing 22 damage over time. Right after that, I use Poison Scalpel, which ends up replacing the level 4 poison with a level 2 poison.
It would be much more interesting if poison were stack-based, starting weak and becoming stronger the more it is applied, or at least if a weaker poison effect did not overwrite a stronger one.
distant wave
zinc thistle
kindred scarab
tranquil yacht