This users name is Giolucca. He blocked the tower I was working on in Babel then went on to work on his.
Well, it’s pretty evident that he griefed the first staircase, but as for the second, it looked as if he was just adding to it.
This is an old report, but I will comment that it does sort of look like he may have been trying to construct something weird there, or connect the two staircases.