What the effects react to
Poison
Poison entities inflict and scale the Poison status on enemies, usually stacking from the start of combat. 9 relics and items are built on it: 9 relics and 0 items.
Updated for patch 0.5.10
Poison from the front line
On Tanks, Poison is often a reply to being hit. Zuri under The Serpent's Kiss poisons whoever auto attacks her, scaling on Defense and Magic; Skorn's Retribution does the same on Defense after Stall (10); Tank's Poisonplate Banner makes every auto attacked Tank apply 2, doubled in 0.5.5. Pimenta's Pepper Spray works by proximity instead, poisoning everything in its cloud each second at a rate set by her Defense. Stall Tanks pairs Skorn and Pimenta with Poison Amplifier, 33% more on every Poison a hero inflicts, and Debuff Mages sets Zuri beside Poison Conduit, whose 150 Poison quest then pays a Magic and an Attack for every 2 inflicted.
Assassins get there through Crit. Yuuna's The Nightshade makes every Assassin Crit inflict 4 plus 4 per rank, the Assassin upgrade Poisonous Eye opens combat with 30 Poison plus 50% of Crit on every enemy, and Assassin's Ambush Engine turns 75% of a Stealthed Assassin's Crit into Poison. Pollen reaches it through Mana Regen, since Sanctuary of Bloom adds a Poison per second for every 5 points.
From stacks to damage
Toxic Contract and Ring of Virality add 50% and 100% to their holder's Poison once their quests, 100 and 175 Poison inflicted, are done. Deceleration Corruptor doubles what is already on every enemy on each of its three Stall marks. The payoffs then read the stack differently: Poison Catalyst deals an enemy's Poison as damage each time it is auto attacked after Stall (15), Poison Ascendancy takes 33% Max HP, 66% Attack and 66% Attack Speed the first time an enemy reaches 50, and Venom Amplification Engine adds 4% Max HP whenever an enemy takes 50 or more damage from Poison.
A kill has ended its Poison since 0.5.8, when statuses began stopping at death, unless Poison Migrator moves the stack to the nearest enemy. Slime strips stacks with Rejuvenating Blow, which clears 33% of all Debuffs. Ring of the Leech, Zuri's item in Shard Gen Assassins, pays Crit and HP/S on every enemy Poison tick, and since 0.5.7 ticks on allies no longer count.
Relics and items that scale with Poison
Poison BaubleUniqueAt start of combat, inflict 10 Poison on all enemies.
Poison AccumulatorUniqueQuest: Inflict 50 Poison. Rewards: Gain 15 Shards.
Poison BloomCommonAfter Stall (10 and Stall 20), inflict 10 Poison on all enemies.
Poison VesselCommonQuest: Inflict 100 Poison. Rewards: Heroes gain 20 Attack Speed and 15 Crit.
Poison AmplifierRareWhenever a Hero inflicts Poison, inflict 33% more.
Poison CatalystRareAfter Stall (15), whenever an enemy with Poison is auto attacked, they take damage equal to their Poison.
Poison ConduitRareQuest: Inflict 150 Poison. Rewards: Whenever a Hero inflicts Poison, they gain 1 Magic and 1 Attack per 2 Poison inflicted.
Poison MigratorEpicWhenever an enemy dies, transfer their Poison to the nearest enemy.
Poison AscendancyEpicQuest: Inflict 400 Poison. Rewards: The first time each enemy reaches 50 Poison, they lose 33% Max HP, 66% Attack, and 66% Attack Speed.