Two knots are called n-friends if they share the same n-surgery. Manolescu and Piccirillo defined RBG links, a kind of three-component framed links in S^3, which provide a systematic way to look for 0-friends. In this talk, we will explore how to generalize their RBG-link technique to find n-friends and how certain n-friends have the potential to create exotic simply-connected definite 4-manifolds. Finally, we will focus on a special subclass of RBG links, called k-special RBG links, which can be used to obstruct knots from being (-k)-slice (i.e. bounding a disk with self-intersection number k) in mCP^2.