This supporter is not there for "damage dealing" or "healing/giving mana" but is there to counter the other teams supporters, Let me give a short example.
Demented is on the opposite team, And your team has this supporter. This supporters abilities is there to either stop their supporters from Healing, Stunning ect. By either stealing their spells. Example: target an area on the ground, The next 2 seconds an enemy spell is casted on their allies, your allies in 200 radius gets that spell instead. Could be a healing wave, so it will heal your allies instead of theirs.
There is no sort of spell stealing other than parasites ultimate. This could make a team fight alot more interesting since your supporters cant just stand in the background spamming their spells, if not targetted by an enemy that is, But they'll have to think twice before casting a certain spell.
"Glacius throws ice imprisonment on Balphagore, Balphagore had the 2 second buff on from your supporter, the ice imprisonment turns back on him self but with only half of the power/duration" etc.
What do you think? Am i the only one who feels like something like that is missing?