Katarina uses a deck focused on Helical Blessing, a spell set that can be used as an item, which obtains power from its soul cards, so her monsters and other spells allow her to put cards in Helical Blessing's soul in addition to obtaining other skills if a card is placed in the soul.
"Blessed by the heavens, and led by the wisdom of dragons! Luminize! Heavenly Helix!"
"The world is but a dream," "A dream you can grab with your own two hands!" "Guided by the wisdom of dragons, accept this heavenly blessing! Luminize! Heavenly Helix Ritual!" (Coordinated Luminize with Dan)