User blog comment:BobTheDoctor27/Gotcha/@comment-29135115-20150406115348/@comment-5072107-20150407010630

But you missed the theory. Tollubo is actually Light Teridax from an alternate Universe, who disguised himself as an Av-Matoran and then lost his memory during the Timeslip in that Universe. Then in Judgment Day he puts on the Krahkaahn and remembers!