Deadly Brew - WoW Classic SoD

Deadly Brew is a Rogue rune for chest armor. It is learned from Rune of Deadly Brew.
Passive
Grants several improvements to your poisons:

When you inflict any other poison on a target, you also inflict Deadly Poison.

If your weapon does not have a poison applied, it has a chance to trigger Instant Poison as if Instant Poison were applied.

Deadly Poison and Instant Poison now gain increased damage from your Attack Power.