Abyss Shade Walker Monster Mod

What exactly is it doing? As melee character it just melts me and there is literally nothing I can do but retreat and wait -- and that's difficult with all the effect clutter this game has. By the time I realize what is going on I'm already toast.

What type of damage is it doing? It seems to be killing regen entirely -- I'm capped on all other resists so I'm assuming it's some type of non-elemental effect? Chaos damage over time?

Thanks.