Dota 2/Dragonus the Skywrath Mage

""Nevermore to see my Skywrath home, that would be worse than any death.""

Skywrath Mage is a ranged intelligence hero who is usually played as a semi-carry or support who can do tons of magical damage, even as the game drags on. His Arcane Bolt scales with his intelligence stat, letting him maintain a high damage output throughout the game with the right items. His Concussive Shot is a useful slow and deals damage in an area of effect. Ancient Seal is a useful disable, while rendering Dragonus' target more vulnerable to his other spells. His ultimate, Mystic Flare, does huge damage in an area for a short moment, capable of killing most similarly-leveled heroes that stays in it for the whole period. While he has below average physical damage and agility, Skywrath mage more than makes up for it with his sheer magic damage.

Arcane Bolt
Arcane Bolt launches a slow-moving projectile at the target, doing damage depending on your intelligence. It is a spammable nuke that scales quite well into the late-game, when other spells generally become much weaker. The low cooldown and cheap mana cost lets you use it repeatedly.
 * Ability: Target Unit
 * Affects: Enemy Units
 * Damage Type: Magical
 * Base Damage: 60 / 80 / 100 / 120
 * Intelligence Damage Multiplier: 1.6
 * Mana Cost: 70
 * Cooldown: 5 / 4 / 3 / 2

Concussive Shot

 * Ability: No Target
 * Damage Type: Magical
 * Shot Range: 1600
 * Damage Radius: 200
 * Damage: 50 / 100 / 150 / 200
 * Slow Duration: 4
 * Slow: 40%
 * Mana Cost: 110
 * Cooldown: 20 / 18 / 16 / 14

Magic Seal

 * Ability: Target Unit
 * Affects: Enemy Units
 * Magic Resistance Multiplier: 18% / 24$ / 30% / 36%
 * Duration: 3 / 4 / 5 / 6
 * Mana Cost: 80 / 90 / 100 / 110
 * Cooldown: 11

Mystic Flare

 * Ability: Target Point
 * Damage Type: Magical
 * Radius: 270
 * Duration: 2
 * Damage: 600 / 900 / 1200
 * Mana Cost: 350 / 575 / 800
 * Cooldown: 60 / 40 / 20