What the crap is a poison mage? It seems like everyone has a different definition.
It is a DoT/sustained damage champ? Is it someone who cripples or disables? Does it do % health damage? Is it AoE miasma or a single target thing? Is it a champ that removes poison for added burst damage? Is it an old school D&D mage who kills you if the cleric forgot to bring cure poison? Why does poison magic turn you to stone while I'm thinking about it?
Sona Ping3 votesPoisons in video games are DoTs.
Linna Excel1 votesThat's the usual convention but it doesn't have to be that way. Elise's Q in both forms is an example of it not being a DoT effect. Then you've got gasses that blind, stun, slow, etc without doing damage but could also be qualified as poisons.
The other problem with a poison mage is Cass always had a spammy Twin Fangs, even if it was bugged forever. So she's never been completely DoT.
Sona Ping1 votesWell, yes, it doesn't have to be that way; a game could do other things. Like in Skies of Arcadia, poison cancels regeneration and that's on top of the simple damage over time.
But I was speaking mechanically. For Elise, Elise's Qs are poison in their name, in their flavor text, because Elise is a spider, but they are only poisons superficially. Mechanically, Elise's Neurotoxin isn't any more a poison than Maokai's Twisted Advance is.
So, if someones is being called a quote "Poison Mage" and they are in a video game, what that means, what that combination of words says, is that they are a mage-type character that does damage-over-time to such a significant extent it defines them. Yes, in the actual implementation you could have things like a slow-poison or a stun-poison or whatever. But what I am saying is that is what that term, "Poison Mage", would mean in context of video games.
The other problem with a poison mage is Cass always had a spammy Twin Fangs, even if it was bugged forever.
I reckon that's more a symptom of Cassiopeia's Deadly Cadence.
Stratavotis1 votesa poison mage is someone who debuffs and dots their enemies. Kinda like a warlock in WoW, but with nature damage. In League of legends, we have 3 variations on that. 
, who is funny for the whole 'you brought this on yourself" from trying to chase him with his poison trail out, 
with his poisons on every auto attack, and mushroom traps, and 
who is both snake and gorgon based. she tosses out her poisons before making the final strike, and if you get too close to her when she's ready, you'll be gone.
Linna Excel1 votesWhat about 
?
Stratavotis1 votes is more of a burst assassin. Her spiderlings are individual units, and her Qs are based on missing and max health. Her venoms are meant to be more of allergic reactions that are immediately fatal (especially spider Q).