Take someone's money, and you must help them avert disaster.
Eat someone else's food, and you must work for them.
That logic did not suit someone like Roy.
But for an old man like Whitebeard, who possessed a strong pirate's sense of honor, it was perfectly fitting.
Moreover, once Roy spoke, Whitebeard had no room to refuse.
Because this was one of Roy's tests.
Although Roy knew Whitebeard was a man of honor, if he turned out to be someone who broke his word, it would be an enormous loss for Roy.
After all, this was the world of the Pirate King. On these seas, deception and schemes were everywhere.
There was no absolute safety, nor was there any absolute adherence to promises.
Roy could not take risks, because he was still weak.
If Whitebeard honored their original agreement, then he would receive the treatment of an honored guest from Roy.
If he betrayed his word, or if Roy detected through his sound abilities that his thoughts did not match his words.
Then Roy would take coercive measures.
Golden Lion would be Whitebeard's fate next.
After all, Roy could not possibly pay such a great price to heal an unruly beast.
And that beast also knew the secret of Sky City's existence.
Roy's means of keeping Whitebeard in check were actually very simple.
When Trafalgar Law operated on Whitebeard, he had implanted two capsules in his heart.
One capsule was filled with Seastone fragments.
The other capsule contained a tiny piece of Dyna Stone.
If Whitebeard showed any signs of becoming uncontrollable, Roy would activate the capsule filled with Seastone fragments and release the Seastone to restrain Whitebeard's abilities.
Of course, if Whitebeard resisted too fiercely and was determined to escape.
Then, when there was no other choice.
Roy would