Fountain of Youth.
The Assassin Alliance's unique artifact. The Bai clansmen could get a few springs of the Fountain of Youth each year, half of which was offered to the South Wizard Alliance.
It didn't have many effects, and in fact only had one: extending someone's lifespan.
A stream of the Fountain of Youth could extend someone's life by more or less 30 years. The results would quickly decline with repeated uses.
Marvin brought Isabelle to the Assassin Alliance to see whether she could be qualified to become one of the highly regarded Assassins, and then think of a way to receive a portion of the Fountain of Youth's spring.
But now, a Fountain of Youth's spring was placed in front of Marvin.
Marvin didn't have any reason to decline.
This thing was a priceless treasure. Those Wizards on the verge of death were willing to spend all they had to buy a Fountain of Youth's spring.
