Spending time with Xue'er was something Damien rarely got to do, but now that he had a modicum of time, he could finally spend a few days appeasing the grievance of this little sister that he'd been neglecting for so long.
While it was a shame that he couldn't take her out of Theavel to enjoy the sights of Grand Heavens Boundary, he did his best to make up for this by providing Xue'er an experience like she'd never felt before.
Using Void Mana and his absolute control over the Sanctuary's laws, Damien could essentially do anything as long as it wasn't at the level of resurrecting the dead.
As such, building a few amusement park rides, a movie theater, and other novel entertainment areas wasn't a problem at all.
For Damien, the definition of fun was his memories of earth, those days when he could game and watch tv as much as he wanted, when he could go out and experience the beautiful nightlife of his home city and enjoy weekends with his friends.