Q: Why can't I use the reinforcement slot? I have a Calling Circle structure set.
A: You must have a Mythic Hero of the current season with the Raiding Party Call or Defensive Team Call mythic effect to use the reinforcement slot.
The Mythic Heroes with these Mythic Effects are those who appear on or after Ver. 9.0.0, such as Rune: Source of Wisdom.
Additionally, only the following Heroes can be set in the reinforcement slot:
・ Legendary Heroes of the applicable season.
・ Mythic Heroes of the applicable season. For raiding parties, these are Light and Astra. For defensive teams, these are Dark and Anima.
・ Heroes who have been granted the blessing applicable to the season. For raiding parties, these are Light and Astra. For defensive teams, these are Dark and Anima.