First time SuperRiddler came on the scene... was back in the bedroom days. He'd roll in, not completely materialized, showing the heavy green tints of his dimension... and he just stood there. It seemed sometimes like he'd come in to even the balance between good and evil, but no one could tell if the bosses were "good" or "evil"...
He always had the latest in weaponry, none of us could keep up, and I'm certain he could take someone out with just a look. He'd just need your name, or if your number was up, you'd start saying your prayers.
Actually, I could've sworn he had this power that cast these circle shaped particles that threw someone across the room. It never hurt them, but it made it clear we were just his playthings, like he was some kind of extradimensional child and we were his toys...
I think the sightings are less frequent now, possibly because we moved into space, and subsequently another dimension. I can only assume it's because he can't manifest there as easily, but I don't know.
We don't know who he is, where he's from, why he comes, or even when he'll come, but it's clear he's here to restore some kind of balance to the universe... based on his own twisted definition of balance. Regardless, just be glad he's fighting for us, for now.