I have no idea what will be there on 80 elite instance, but hey, what's you point? you don't want to get pains or others to get them? Even if there IS pain fragments, it will probably take more thana month to get enough fragments..
Also, you have some wrong idea about levelling system. After 70, levelling becomes very slow and it will be like 1-2 week till you get enough xp for 1 level up. I'm at almost at level 77 myself and it will take me about 10 days to reach 78. I'm pretty sure level between 80-90 will take quite a while and by then, a lot more ninja's will be added and pains will start to lose their superiority..
Don't think of pains as some omnipotent characters. Just enjoy the game and keep getting stronger.
Btw, clearing plot instance 9 will give you Gakido, though as per trend you may have to hit level 90 to get it.