Here's Pabro with more info:
"Follow the footsteps of ancestral champions along the many branches of the warrior's path, and celebrate the legends from the past during this year's Lunar Revel. Lunar Goddess Diana, Warring Kingdoms Tryndamere and Dragonblade Riven echo history as they enter the battlefields, ready to inspire your next victory.
Find your way along the warrior's path with new and returning Lunar Revel wards, and celebrate your allies by bestowing mystery gifts. As you progress, you'll earn the icons of this year's three legends, and perhaps learn something more about your own journey. Revere the past and celebrate the promise of the future during the Lunar Revel in an upcoming patch!
Return to leagueoflegends.com for more information as the Lunar Revel event draws near and we'll see you on the battlefields!"