It's hard to believe this guy was the source of problems plaguing throughout the Universe of Kingdom Hearts. He was the one that banished Ansem the Wise, encouraged the other apprentices to do things that shouldn't have been done in the first place, created the artificial Heartless and sent Kairi to the Lanes Between (Lucky that Charm spell of Aqua's saved her, sending her to Destiny Islands.), split himself to two beings: Ansem, Seeker of Darkness and Xemnas, the Superior of the In-between, and finally caused all Worlds to fall into Darkness for 10 years.
Now, we know the history of how it came to be and we know what the future entails in Kingdom Hearts 3, how would you envision the future of Kingdom Hearts Universe once this man, Master Xehanort and his 13 Seekers are defeated?
Personally, I would say it would take years to repair the damages caused by Xehanort after the final clash in KH3. I mean, that war of that magnitude would probably cause some rifts in the Worlds and it would take some time to really fix it up in good condition.