Quoted By:
Assuming this is for use in game:
Black Sludge vs Leftovers doesn't matter since you won't be running Trick and the AI (almost?) never uses it.
I'd drop leech seed for another attacking move unless you're doing PWT or Subway, either Earth Power or Earthquake, just for the extra coverage and PP. Leech seed is great since it's a guaranteed kill against most the AI opponents, but it's fairly slow.
Alternatively, replace sleep powder with EP/EQ, if you have a more reliable sleep user on your team (faster, higher accuracy sleep move, etc).
And of course don't bother with hidden power ingame.
