Heroes of the Storm - Free to Play Hero Rotation: May 3 - 10, 2016

• Li Li
• ETC
• Jaina
• Butcher
• Gazlowe
• Lt. Morales
• Diablo (Slot unlocked at Player Level 5)
• Illidan (Slot unlocked at Player Level 7)
• Greymane (Slot unlocked at Player Level 12)
• Dehaka (Slot unlocked at Player Level 15)

Source: http://eu.battle.net/heroes/en/forum/topic/13604571130?page=4#66