Chain Challenge is a special game mode in which you clear several Story Maps in a row, to earn Hero Feathers and Orbs. In order to unlock a level of Chain Challenge, you need to first complete the corresponding Chapters in the Main Story/Paralogues.
There are several difficulties to select from, listed below are the difficulties and types:
Type
Stamina
Teams
Battles
Single Chapter
20
2
5
Double Chapter
30
3
10
Single Paralogue
20
1
3
Double Paralogue
30
2
6
Defeated Allies Can't Be Revived[]
If all of the allies on a team are defeated, a new team of allies can be immediately created to try the map again. However, be aware that the allies that were defeated cannot be used again for the rest of the chain challenge. Be aware that allies will continue to the next map in the set with the same HP and cooldown as when they finished the previous map.
It's a Battle of Attrition[]
After one team is defeated, if a map is entered again with a different team of allies, the enemies defeated by the previous team will not reappear. Any surviving enemies will carry over the HP they had before, and their Special cooldown will reset. If no damage was dealt to the enemies with the previous team, their starting HP will be reduced by 20% so they will gradually become easier to defeat.
Rewards[]
Rewards are based on difficulty and whether you complete a single or double Chapter/Paralogue.
Hero Feathers and 
Orbs. In order to unlock a level of Chain Challenge, you need to first complete the corresponding Chapters in the Main Story/Paralogues.
