Thread:Silver-Haired Seireitou/@comment-5651818-20141103024600/@comment-2089817-20141119143304

Seireitou was full Shiroyasha during his days as a Captain. It wasn't until he defected and ended up in Yuanrang that he finally started mellowing out. It was during that time that he had begun his mastering of Hakuda. And it was over several centuries there that he had become the beast you see today.

In regards to Sei's darkness influencing Gekko, perhaps this means Gekko's chaos has been riled up and even matured to produce an internal darkness. Memory-wise, I'd say he would have obtained some degree of the vicious acts Seireitou committed while as a Captain, and subsequently, he would have inherited some measure of his vicious fighting style from back then; the details of which you are free to interpret.