User blog comment:-Saryn-/Feitan's pain packer/@comment-14902757-20140413062727

Interesting. I also had this question in mind when Phinks said to Kalluto "the one he's using this time." It definitely means there are more than one. I went back to that episode and so here are my analyses.

1) We can throw in any number but we can never say for certain until it's revealed in the future (wishful thinking) by Togashi himself. According to Wing-san, nen can evolve and since the strength of Pain Packer varies depending on the amount of injury Feitan receives and how pissed he gets, then it's quite possible that there's no exact number and quite possibly even Feitan still has room for more abilities that even him hasn't used or thought of yet.

2) I don't think it's elemental nor is it based on planetary bodies. It's probably more based on Feitan's degree of anger or how pissed he gets. The name: "Unforgiven:Burnt by the Sun" sounds to me like a verdict or a decision how he receives the pain/hits he incur from enemy attacks. It's somewhat related to the fact that he's the Troupe's torturer. And so his nen ability has something to do with transmuting pain, if there's such a thing. Also, one other thing Phinks mentioned is that Fei's abilities have wide attack radius. So Pain Packer's other form of attacks could be explosion (I'd imagine it has a form similar to that of Youpi's), acidic air/mist (just so an armor is applicable)...

3) It's possible that it has different appearances. That's probably how Phinks knew what's coming... I believe the armor is specific to protecting him against his own ability. Assuming it changes types, then it means that it has something to do with what power he uses. Thus, the armor could be vulnerable to very specific enemy attacks. It's hard to come up with an example of an attack that would work against the armor he conjures but I believe it's not impregnable.