Obeliskos is one of the many older forum-goers, if you've seen any of his posts, chances are they were made in jest.
He normally hangs out with Darkfire1004, because his life's work is to get into her pants. He also has a secret cereal fetish.
Is the creator and proprietor of the Ulmf wiki. (according to his profile page anyway: http://ulmf.wikia.com/wiki/User:Obeliskos)