This is one of the least used masteries, apparently only champions with DoTs benefit from it though, most poisons are AoE meaning that they apply the reduced effect... right?
Also, did they ever fixed Ezreal's Q interaction with it? I think this would be an interesting choice for a keystone if it wasn't so heavily gated.
yeulx1 votesyeah thats pretty much true tho those champions are fking strong with it... :~: nightmares when 
hits u with a Q and the poison and the DFT does over 1000 damage
Quepha1 votesSingle target applies 4 seconds AoE applies 2 seconds DoTs apply 1 second
If the DoT is produced by an AoE, like Cassiopeia Q, then it still qualifies as a DoT and applies a 1 second DFT every tick, for 4 seconds total duration.
Some spells are kind-of fuzzy on what they qualify as. Cassiopeia's W seems to count as a DoT, but Morgana's W which applies damage in the exact same fashion (periodic damage to enemies standing on the area) is treated as an AoE. Swain's Q which seems to clearly be a mult-hit attack that should count as a DoT actually counts as a single target spell while Zyra's plants count as an AoE.
Ezreal's Q does not apply spell effects so it should not apply DFT.
Hige1 votesYeah I mean, the mastery itself is pretty clear and the cases where it works are, for the most part, well defined.
What I'm trying to say is that it occupies a keystone mastery spot but it's so niche that it feels almost like a waste maybe? if it wasn't this odd maybe thunderlord's and fervor wouldn't be so mandatory.
I personally would like it to be a poking keystone, since we have a consistent dmg one (fervor) and a burst dmg one (warlord's benefits from huge crits).
Atanchan1 votesThe reason why Morgana pool doesn't proc DoT effects is because "DoT effects" doesn't actually refer to DoT effects; it refers to damage dealt by debuffs, which are almost always DoT effects, but not all DoT is done through debuffs.
In Morg pool's case, the ability basically puts down a thinker that deals AoE damage every second. Same case with Swain Q, except it doesn't deal AoE damage, only damage to a locked-onto target. Cass W, on the other hand, is a thinker that places a debuff to enemies in its AoE that deals DoT damage - notice how when people step out of it, they still take damage from it, as the damage is actually dealt through the poison they get when they step into it.
It's like how Rammus R and Sunfire are different; both deal damage to enemies around the user periodically, but Rammus R just flat-out does AoE damage around him while Sunfire places a debuff on nearby enemies which deals period damage. This is noticeable in that multiple Rammsues ulting will stack their damage, whereas multiple Sunfires won't.
Quepha1 votesthat places a debuff to enemies in its AoE that deals DoT damage - notice how when people step out of it, they still take damage from it
That's not how it works anymore. Cass's new Miasma only deals damage while the enemy is standing on it. When enemies leave Miasma they immediately stop being affected by the slow, grounding, and damage.
Atanchan1 votesWell, still, given how it interacts with other stuff - like Deathfire - the damage is still done by debuff. Which ... isn't that big of a surprise, considering otherwise it would require more work to make sure standing in two of the spots didn't make you take damage from both, plus they needed the debuff for the slow and grounding anyway.
DeathBurst1 votesI personally think that Deathfire is under-rated. Any AP champ that want to focus on the late-game and that isn't an Assassin should take DeathFire instead of Thunderlord. Thunderlord is better in early game, but DeathFire VASTLY outclasses it in late game.
Calabok1 votesThere's no torch