Anti Mage is the most popular agility type hero in Dota 2. He also become a favourite hero of Miracle. His high agility and low base attack time giving him advantage for killing enemy hero and creeps. Not only that, he also can survive so easyly with Blink skill.
For harassing enemy, specially caster type hero, Anti Mage have Mana Break skill. With this passive skill, Anti Mage can burn enemy mana pool. For each attack, Anti Mage will burn 64 mana and burned mana will giving extra damage to enemy unit. ( This skill work on illusions too ).
For chasing or running from enemy unit, Anti Mage can use Blink. With this skill, Anti Mage can teleport to the specific location. Anti Mage also can enter and out combat with this skill. For your info, Blink also disjoint every projectile coming to Anti Mage when casted.
As a Anti Mage, he also have a spell shield who can give him extra resistance to magic. Magic resistance bonus up to 50%. Amazing right ? ( Can be upgrade with aghanim scepter causing the spell casted to him will be blocked and reflected to the caster ).
His ultimate skill is Mana Void. This skill is a big bomb to every magic caster in Dota 2. The more manapool you have, the more damage output will be taken. This skill depends on how many mana loss. Damage per missing mana is 1.1.