Have you ever used the "Evil Twins" trope?

[Satyrn]

Yes, during the time when we were rotating DMs. I introduced the first evil twin, then tripled up on the idea and introduced a third twin. Then the next DM, to my great joy, introduced a fourth evil twin . . . and an explanation for why there were actually dozens of evil twins still to be found.

. . . So evil dodectuplets rather than twins.