Night Stalker

Balanar the Night Stalker is a unique melee strength Hero in the sense that his abilities are affected by the time of day during a game, becoming much stronger during the night. He is usually played as a ganker due to his passive, Hunter in the Night, making him formidable and fearsome during the night. However, he's greatly weakened during the day, and is a very easy target if caught off guard.

Trivia

 * Some people call him "The Legal Map Hack" after getting Aghanim's Scepter due to the unobstructed vision at night.
 * Night Stalker is one of the few heroes to have 1800 night vision instead of the usual 800 (however his day-time vision is much lower than average).