The Create Card is able to give existence to anything written while it's in its visible form: a mostly blank storybook. There is no limit as to what can be brought to life, provided the writer keeps Create opened and filled with words. It can also give the writer inspirations for what to write. Things created by Create can interact with their surroundings, both for better or worse, however its power is only active at nighttime.
In Episode 31, Naoko Yanagisawa, after buying Create from its hiding place in a bookstore, writes a story in it about princesses, flying animals, and a dragon. All of Naoko's imagined creatures, all having spiral-like eyes, come to life a short distance away in town. After its capture, Sakura uses this card to fight illusionary monsters, both for training and for Tomoyo's video recordings.
Create's Sakura Card transformation is not shown in the series. However, Create is seen being transformed in Tomoyo's Video Diary 2 to create a lemon cake to trick Kero with. The Create is under Light.