Prairiefox
The rolls of the dice determine the battle order. The only time it doesn't is if two people on the same team both have a speed+ nature.
The lowering of speed I believe would only affect it RP wise, not the mechanic so the order specified would stay the same, unless someone used Quick Attack or any other first turn priority moves
Kk, thanks
Btw can you list the pokemon both side use in the referee post?
I am at loss of who to attack since i don't know what pokemon my opponent picked.