How are your challenge runs going?
Any deaths? Challenges? Losses? Good luck? Bad luck? FUN? etc.

I've been doing a lot of modified challenge runs and by far the most fun rules are those as follows:
Catch any individual one Pokemon from the first three encountered in a route.
If a Pokemon has not been part of your party for the past two gym battles, you must release it.
No grinding beyond five levels higher than the highest leveled wild Pokemon encountered.
Otherwise base Nuzlocke rules apply.

It's given me by far the most enjoyment and challenge so far. It gives you the opportunity to fuck up and get a critical without being shorted a Pokemon as well as the chance to take a risk for a better one once or twice if you get boned. The leveling constraint is more of a personal thing because I always tend to grind beyond all chance of failure if I don't make it a rule for myself. The gym thing I randomly threw in on a past run and it turned out to do wonders for how seriously I took the whole "team" thing.

How about you all? What modifiers have you enjoyed the most?