It DOES stack with single-target disease, but I think at your level it's not really worth it. It's not a line of spells, it's only one- Infectious Cloud. Your other AoE spells you get later are rain-type targeted DD's. IC is useful up until about 24.

At your level, stick with the ol' Enstill plus poison plus disease. Can slow and add pet damage if you're feeling spicy.

EDIT: Sorry, didn't realize this was blue and you were twinked to the gills. Just melee your brains out with a slow, add DoTs if you want more DPS, profit.

Not me, sorry I hi-jacked the thread so your advice applies, thanks.

Ah, yes I see that now. Sorry.

As a side note: Push to 44 ASAP. The 39-44 pet upgrade is exponentially better than the 34-39 one. Plus you get Togor's. At 44 I was able to Togor, sick pet, Scourge, Poison, Enstill and then just sit and med while mob died and pet would barely take any dmg. More mana-efficient than root-rotting with no pet, which means you can take 2 HG's or Spectres at a time.