This is a major event running between September 12-30th, 2019 in the free to play mobile game, Kingdoms of Heckfire.
Top prizes in the event include legendary dragon shards, speedup items to build your city and improve your research, and exclusive avatars.
Get the game here on iOS: https://itunes.apple.com/app/kingdoms-of-heckfire/id1209396965?mt=8
And on Android: https://play.google.com/store/apps/details?id=ata.kraken.heckfire&hl=en