This is a kind reminder: Changing a Hero into Costume applies to all of your teams with that Hero. This may affect the lineup strength in your Defence Team. Alliance War and Raid Tournament Defence teams cannot be changed once they are in the active phase. This means that if the Costume is equipped, it will define the Hero’s Level and Strength.
We are working on implementing a confirmation to ensure no Hero Costume is equipped accidentally.
As this is a brand new feature, we will be monitoring it and making further adjustments based on our findings and player feedback.
You can find information on this and any other questions you may have on our Support Page.
We thank you for your understanding and our apologies for any inconvenience this may cause!