OMFG. *Deep breath*

Leave. The. Kernel. Installed.

Don't touch it. Don't **** with it. Pretend that package that says "remove this package" doesn't exist.

That message is not out there for the users. For frak's sake, look at the version numbers of the power kernel package you have installed, and the one in the repos that says that. (Hint, the version number of the one in the repos is ridiculously smaller than the normal one you already installed.)

This is because the oldest versions of power kernel used an entirely different approach to some of the things Power Kernel does. At some point, two packages got created, and this one got left over. Therefore the developer changed the description and name of the older package, to say that the older package is obsolete. The newer package (the one you have installed) is NOT obsolete.