From King's Raid Wiki
Devoted Servant costumes can be bought from the Special Shop and gives 2% gold boost and 4% EXP boost. They were made available after the 8th November 2018 and 22nd November 2018 patches.
|Special Shop||School Season, Beach Party, Trick or Treat, Super Star, Merry X-Mas, World Fair, Frozen Fantasy, Academic Flair, Wedding March, Summer Tide, Tender Embrace, Devoted Servant, Yuletide Carols, Witching Hour, Culture Ensemble|
|Event Costumes||Darkness Costume, Sub Story, League of Honor|