If Shadow was created by Eggman how come Shadow wants to save the world

Shadow was created by Eggman's grandfather, Jerald Robotnik. The reason he created Shadow was to protect the world from the return of an all powerful alien (Shadow the Hedehog the game) Jerald's neice Maria died in the attack on the lab where Shadow was made and her dying words were along the lines of "give the humans a chance, a chance to be happy." So Shadow tries to save the word because Maria told him to