The Hero Calendar was first introduced back in Winterfest 2016. It's a calendar with 5, 10, or 14 doors, every door offering sweet rewards. Players can earn 3 kind of keys to open the doors, each day one door. Doors reset when you opened them all at the last day and you open them again in any order.
- Agnon ascended and dark doors opened in February 2018.
- Deadeye was introduced in the Deadeye's redemption Hero Calendar starting on June 22, 2018.
- Iris was introduced with a hero calendar starting on August 24, 2018
- Niveous was joined as 100th Hero with a hero calendar during the Frostfire Valentine's Event, starting on February 14, 2020 It was a 10 doors calendar event. A Dragon Pass (in-app purchase) offered 10 extra doors with tokens for Niveous.
- Lorelei flew into the game on March 18, 2020. The "little" Pixie is the 101st Hero. It was a 10 doors calendar event, and Pixie Pass offered 10 extra doors with tokens for Lorelei.
- Crucible was introduced in the Trial by Fire Hero Calendar starting on May 13, 2020. It was a 5 doors calendar event and the Legendary Igniter Pass offered 5 extra doors with tokens for Crucible.