A support with several powerful area abilities for team fights.
In the early game, you fight with the area root of her 1st ability and harass with her 2nd.
Taking her ult unlocks a 4th ability.
Enemies can slip through her 1st ability if they move well, so use it when they can't move freely, or follow it with her ult to fear them. You need to be creative.
Her 2nd ability only makes her untargetable, not invulnerable. (She can still take damage from area attacks, so be careful.)