Ok. I really like this new feature, but there are a lot of strange things.

First, the boss guarding it repeatedly oneshotted me when I first encountered it -- I came back to the game to find that it was a glitch and it doesn't do that normally.

Second, the levels seem to be completely nonpersistant -- What happens if you leave the level with the portal out on it?

Third, there are stairs up on the first level to "Randomplace(0)". And stairs up on the resulting level. And before you know it you're bashing level 5 monsters in "Randomplace(-16)"

This is in b26.