>>48939254>Staraptor's real threats tend to be Rock attacks or Electric moves, and Infernape can't really switch into those well, not unless you know you can KO the mon immediately. Meanwhile, Staraptor switches in on Infernape's nasty ground weakness. It's why I said the two complement each other very well. Staraptor's intimidate protects Infernape from getting OHKO by the mostly physical rock types, and a STAB close combat from Infernape can OHKO quite a few rock types in return, especially if it's holding something like a fist plate or life orb.
Electric types tend to be special attackers, so switching Infernape in vs them is riskier, but if you lead with Infernape and it has earthquake, it can potentially sweep them. The versatility is important cause in Nuzlockes, you may not always encounter a Pokemon that's the perfect counter to something. So in case you don't have something like a Quagsire or Gliscor available to you, Infernape can be a stop gap. It may not always be the number 1 option if your encounters were perfect, but it can be your best option in a lot of scenarios if they weren't.
