IDEA (bad idea) but an idea
Support Cassiopeia
Take a Snake
Will do
Take a blue build
or 
if you need wards
Then
(Not optional, it's blue for a reason)
So that'll do.
Max Q in lane if you want to poke or E if your ad feels like they wanna all in (Don't max W you are the real carry anyway)
Mid Game try to make some pick with your consistent slows (normally Rylais before Hextech GLP) Else, I recommend farming for late.
Once you hit late game, non escape, non reach you, and for one you can peel for your carries with "unescapable" slows, groundings, and an Aoe stun.
You will have high damage (Cause late game Gorgon)
And your lane phase (as long as you don't go to crazy on spending mana) is decent if you hit your poison on an ADC or squishy support.
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:D
