If Yan Chen had made this promise to Qiu Tu, Qiu Tu would have mostly taken it as a joke.
After all, when it comes to what Yan Chen says, nobody knows how much is true and how much is false.
If it were Tang Feifei who had made the promise to Qiu Tu, he would also keep it in mind, planning to use it if an opportunity arose, or disregard it if it didn't.
After all, though Tang Feifei is someone who keeps her promises, she also carries the pride of a major family's direct lineage: she would remember your favor, and if you sought her help, she would lend a hand.
But if you didn't seek her out, she wouldn't regard you any differently because of the favor.
After all... there were too many people willing to help her on a regular basis.
But... this promise was made to Qiu Tu by Liu Xiongyuan!
In this period of time, through interactions with Liu Xiongyuan and various pieces of intelligence, Qiu Tu had come to understand Liu Xiongyuan's character traits.