[quote=@The 42nd Gecko]
Does it count as a character participating in a battle, if a character lays a blessing spell on someone pre-fight and then stays home?

Aka, if Miyu just goes "And now your Armor is Mantle of Unconquerable Sun'd for a minor defense boost" to Henry, and then stays home, does she count as a participating character?
[/quote]

No, since it's before the battle.