Invoker

Overview
"Grovel, you worm!"

A deadly flame-based ranged caster unit that has high area control capacity and relentless burst damage.

Abilities
Guided Fireball: Fires a guided fireball that deals 100 damage to a target hero, it curves as it nears your hero, it is extremely easy to side step the fireball once it gets close. Leaves a small patch of fire that can and will deal damage to the hero standing in the area upon fireball detonation.

Flame Surge: Summons 5 pillars of flame, that have small gaps inbetween to escape from, each dealing 80 damage every 1 second. They close in after a few seconds, dealing 400 damage to the unit caught in the middle.

Strategy
These enemies should not be taken lightly when encountered, once they throw their curved fireball, side step right before it hits you, or else you will suffer a fairly decent amount of damage.

Once they cast Flame Surge, move through one of the few gaps to avoid taking the damage.