Fortunately, You got rid of him early. He came on my old wiki that I never go to anymore, and did so much vandalism before i noticed and got him blocked. He's so out of control, I reported him to the VSTF.
@Davidbw58 Same thing happened to me. He came to my Wikia for forumers only and tried to vandalize the pages until I blocked him. Good thing I blocked him just in time before he could’ve done more damage.