Solomon's Excalibur

"Why did you leave your arm with that snake woman?" Dia asked as she handed him the cup. "Maybe you could have had it reattached or even healed." 

"I paid the price to get out of that place alive," he accepted the water with a smile. "The arm wouldn't have been preserved the way it is without her powers." 

Arthur could place the arm in his subspace, but he wasn't sure it would be preserved the same way that Larza's ability worked. Her powers worked to isolate things without severing their connection to the world, and that's why the soul restructure made it impossible to regenerate or attack his arm. 

To put it simply, Arthur needed less time to heal because Larza used her ability to sever his arm and isolating it.

"Is it weird if I said I like you better this way?" the princess said with a thin smile, and Arthur almost spat his water. 

"Uh, armless?"