It's obviously referring to King Harkinian.
In the new Nintendo power magazine, it is said that Ghirahim talks about resurrecting his master! Who could this be? Someone we know or someone entirely new? Do you think Ganondorf in OOT be a reincarnation of this master, and that is what is meant by his rise to power in OOT being elaborated upon? This would mean the multiple Ganon theory is correct and that he can reincarnate.
If it's not Ganon do you think it will be a new evil, or something mentioned in other games e.g malladus?