The Fated Summon is designed to ensure that players are rewarded with at least one Legendary Hero after making a certain number of Hero Summons.
The bar in the top left corner of the Summon Gate selection menu visually indicates your progression toward the Fated Summon. Every time a player draws from a Summon which includes Legendary 5* Heroes, but does not receive one, their Fated Summon counter increases. Once the counter is fully charged with 100 Summons you may choose one Hero for free from a list of 20 Legendary Heroes. Most Summons in the game count toward the Fated Summon, but there are a few exceptions:
Legendary Heroes do not count towards the Fated Summon
Daily Summons and Troop Summons will not charge the Fated Summon
Heroes and Trainer heroes from Bonus draws do not count towards the Fated summon, but Trainer Heroes obtained from "regular" (non-bonus) draws DO count towards the Fated Summon
Please also be aware of the following:
All players are shown the same list of Heroes. Each Hero may be claimed only once
Once the Fated Summon is fully charged, you may want to "reset" your Fated Summon counter by redeeming a Hero before making any more Summons. Summons made when the bar is already full will not count toward your next Fated Summon
Redeeming all Heroes on the list will not automatically refresh or restock the Fated Summon. If you have already obtained all 20 Heroes, your "counter" will be frozen until the "next" Fated Summon is announced!
The Fated Summon will be "restocked" every once in a while, and the list of obtainable Heroes may change when this happens. But don't worry — your "counter" will not reset when the selection of Heroes changes