I'm just wondering about retreat costs with these guys in play on
opposing teams. I want to know whose Pokemon Power comes into action
first. If Dark Muk and my Dodrio were both actives how much would it cost
me to get that Dodrio out of there. If the Dark Muk's power goes first my
free reteat is jacked up to 2 then reduced by one due to retreat aid. But
if you factor my power first my retreat isn't -1 it stays at 0, this 0 is
hiked up to 2 due to Stinky Finger or whatever that power is called. So
what is the retreat cost??? And on a related note... Can I retreat my
active to promote a benched pokemon and then later in the same turn
retreat that fresh active for the original active who was just benched???
Pretty much what im asking is about free Poison healing(and Confusion
healing to some extent) if you have 2 pokemon in play with free retreat
costs. I hope you can help me, cause i like Dodrio and want to use him
properly. Thanks

Well, it's funny.  Allow me to explain the situation.

First of all, Pokemon does recognize the existence of negative numbers.  This could be important.  Secondly, Pokemon Powers are all applied simultaneously unless said otherwise.  So, theoretically, the retreat cost would be (0+2-1) or (0-1+2).  Either way, it is still 1.  Even if applied in a different order, it could be 0-1 = -1, and -1 + 2 = 1.  No matter what, the retreat cost would still be only 1.

One slight problem, though - Dodrio's Pokemon Power only works from the bench, and would not be in effect against an active Dark Muk if the Dodrio itself was active.

Scott