Hello!
First of all, thank you for this very unusual game!
I am coming from DCSS and I see that stairdancing in Demon is even more overpowered than it is in DCSS. I use Ctrl+movement to retreat to stairs, then focus a single enemy, kill it and retreat to previous level to heal. After healing I resummon some allies, use the stairs, kill another enemy and retreat via stairs again and so on. It works even with very fast monsters (I lured 4 "blue fish" across half-T:4 to the stairs, dismissing almost dead allies along the way) and very powerful monsters (2 jingashis, if I was unlucky with attacks I just retreated to heal and tried again). Luring monsters to stairs is somewhat tedious and repetitive.
I've read some complaints about it on roguetemple and as far as I remember you were going to do something about it so here are some ideas (probably bad ones but anyway ).
1) Make it similar to DCSS: adjacent enemy monsters go upstairs along with PC, non-adjacent allies stay on previous level (and can die there if are not dismissed soon).
2) Make allies who were not adjacent to PC when retreating via stairs stay temporarily disabled (they cannot be dismissed/summoned unless PC returns back to the level where they were left)
3) Give a temporary penalty for re-entering a level. For example, decrease allies cap to 2 from 3 for 10 turns.