At the end of the Beyond Wonderland series, the Cheshire Cat is killed by Calie, however as with most creatures from Wonderland it does not really stay dead.  Instead it takes the form of a regular cat which is left at the pound.  Lina is an exchange student that doesn't fit into school very well, between her promiscuous roommate, her roommate's racist boyfriend and the various other girls that pick on her.  Lina decides to adopt a cat to ease her loneliness and inadvertently chooses the depowered Cheshire Cat.  The Cheshire Cat eventually returns to full power and starts dispensing what it views as a healthy revenge against Lina's enemies (which comes down to killing them all.)  Lina is horrified at what he has done, but he threatens her too into becoming his companion.  Later she is shown in Wonderland as Calie has made her way back there to search for her daughter Violet.  She and the cat seem inseparable by that point.