Anyways, Nick believes it's possible to turn Xion human, heart and all, after they discover Xion's condition is that of the physical memory clone from Sora. Through the use of Alchemy, Ruins, and two Philosopher stones, Nick and his wife preform the proceedure.
The problem is, even the philosopher stone has it's limits. As with equivilent exchange, Xion's body regresses from 13, 14 years old, to that of a 10 year old. She also looses muscle control over her bladder and bowels. Mentally, Xion loses her sense of self; all her memories and knowledge, becoming an overgrown baby.
The Flannels are horrified of the damage done to Xion, despite the success of turning her human. To make up for their mistake, they adopte her as her daughter. After a few weeks as their baby, the Flannels discover Xion has gained some magical gifts.