Level 1-
Lethal Injection (Active): Deadly Poison now deals an additional burst of 100(+4%) damage upon the DoT's expiration.
Lethargy (Active): Crippling Poison's Slow no longer decays over the duration.
Enfeeblement (Active): Weakening Poison also slows the cooldowns of all affected enemies by 40% for the duration.
Level 4-
Hemorrhage (W): The target of Assassinate takes an additional 50(+4%) damage per Combo Point spent over the next 4 seconds.
Defias Assassin (Passive): (Quest) Hero takedowns grant you an additional 1% attack speed, up to 10%. Upon killing 10 heroes, casting Assassinate will reduce the cooldown of Stealth by 10 seconds.
Friends in High Places (Q): Enemies hit by Mutilate are revealed for 5 seconds.
Rabble Rouser (Passive): Mercenaries and Minions near you deal 50% additional damage and take 50% less damage from non-Heroic sources. You can appoint a nearby Wizard Minion as a Rabble Rouser until it dies (using the trait button), but you yourself lose the buff until the Wizard dies.
Level 7-
Cull The Weak (Q): Mutilate and the accompanying poison deal 40% more damage to targets suffering from damage over time effects.
Hiding in Plain Sight (E): You now automatically enter Stealth after 5 seconds of not dealing or taking damage, but this Stealth does not grant the damage bonus.
Leeching Poison (Active): Deals 150(+4%) damage over 3 seconds and heals you for 40% of the damage it deals. This heal is doubled against Heroic targets. Toggling to this Poison incurs a 3 second cooldown preventing you from swapping to other Poisons.
Level 10-
Nightmare Elixir (R1)
Backslash (R2)
Level 13-
Alchemist (Active): You can now have two Poisons active at any given time. Switching to a new Poison will replace the Poison depicted in your trait icon, which is the Poison applied the least recently. The most recently-applied Poison deal 40% less damage than normal.
Escape Plan (E): Casting Stealth instantly refills your Energy pool.
Loose Ends (W): (Quest) Every time you cast Assassinate at full Combo Points, Assassinate gains an additional 5 damage per Combo Point, stacking indefinitely
Level 16-
Weaklings (Q): Mutilate and the subsequent Poison(s) deal 30% extra damage to targets under half health.
The Family Trade (E): Stealth increases the damage of your next Basic Attack or Ability by an additional 20%, and Basic Attacking from Stealth now stuns your target for 1 second.
Hopeless Fight (Q): Enemies hit by Mutilate receive 40% less healing for the duration of the attached Poison(s).
Level 20-
Unending Nightmare (R1): Nightmare Elixir spawns two additional Illusions within the Nightmare, and the target now takes 40% of their health pool in damage if they are unable to kill the Illusions.
Frenzied Slashing (R2): If the target of Backslash dies within two seconds, you are able to cast Backslash again for free within a five second window.
Master of Poisons (Active): Your Poisons now deal 60% more damage to all affected targets.
Nexus Blades (Passive)
Heroes of the Storm Build Guides
750
... Nerf that shat.