Any DOT will do the job without reflected damage.
Gravemaker usually does roughly 1/3 direct damage, 2/3 DOT, so he gets hit back but not too badly.
Cheshire Cat, Lady Locke, and Natalya do all their damage as DOT, like Proteus.
The sand people and vampires do a significant portion of their damage as DOT too, but they will get hit back for their direct damage.