High School DXD, Vol. 18 (Light Novel): Funny Angel of Christmas

WE NEED A CHRISTMAS MIRACLE!A holiday party is being held in Heaven, and Issei and the gang are all invited! But as they take in the festivities, a string of mysterious deaths is reported within the exorcist community. The harrowing events occur one after another, and it isn't long before Irina gets swept up in the chaos! Will the Christmas spirit be enough to guarantee her safety? Or will the happy-go-lucky angel have her wings clipped?!