If you control no monsters, or all monsters you control are "Trickstar" monsters: You can Special Summon this card from your hand. During the Damage Step, when your "Trickstar" monster battles an opponent's monster (Quick Effect): You can send this card from your hand to the GY; that monster you gains ATK equal to its original ATK until the end of this turn. You can only use 1 "Trickstar Corobane" effect per turn, and only once that turn.
This card might be based on the Helleborus niger, also called the Christmas Rose.
This card was released in December 2017 in the OCG. Coincidentally, her outfit has a Christmas's feel and her name is probably derived from carol.