Explain to me how your roleplaying rules work in more detail? When you say "we can only use moves from 3rd gen or before", does that mean you can only use moves that already existed in the game, or that you can only use moves that already existed
in that Pokemon's moveset? I know that quite a few Pokemon have gained new "old" moves! (Moves that already existed but which they couldn't previously use.)
Also, does your RP permit the use of new items?
I take it your RP isn't like the anime, and you
are restricted to four moves per Pokemon?
(Would be ever so easy otherwise - put every useful move on!)
Depending on the rules, Beautifly could use:
1. Gust - FLYING, special
2. Silver Wind - BUG, special
3. Giga Drain - GRASS, special
4. Psychic - PSYCHIC / Shadow Ball - GHOST / Morning Sun
Hold item: Big Root or Sky Plate.
Gust has a low basic power - only 40. But this goes up to 60 with STAB, making it as powerful as Giga Drain. And used with the Sky Plate, it's boosted to 72, which is reasonably acceptable.
Silver Wind's a lovely move that can potentially boost all stats. It has a 10% chance of boosting each stat each time it's used. I like it a lot.
Giga Drain sucks HP out of your opponent and restores half of them to you. It could be used in combination with the Big Root for more power.
Psychic & Shadow Ball fill in possible gaps in your team. Morning Sun restores HP. Doesn't work so well if the weather is bad, but I don't like to put Sunny Day on Grass or Bug-type Pokemon.
Shedinja is rather ugh - its 1 HP make it so difficult to use, as well as the fact that Ghost-type moves are Super Effective against it!
1. Confuse Ray / Swagger
2. Shadow Ball - GHOST / Protect
3. Grudge
4. Aerial Ace - FLYING / Dig - GROUND / Toxic ??
I don't usually like to use Swagger because of the risk to your own Pokemon if the foe manages to overcome its confusion and hit you. But Shedinja is probably the one Pokemon that can use it effectively, because it only has 1 HP in any case - if it's going to get KOed by an attack, it'll get KOed! So in that case it seems worth making the foe confused AND more powerful, so it's more likely to do itself serious damage.
Dunno if it's worth putting Shadow Ball on Shedinja - it's pretty slow (base speed stat 40), and it'll be KOed by any Ghost type that it faces. Protect is annoying and will make Shedinja last longer. Also, if you're playing with only 3rd Gen moves, there isn't anything that can break Protect.
Grudge is nasty - if Shedinja faints, the opponent loses
all PP for the move that KOed Shedinja. Again, an effective combination with its 1 HP.
I guess Shedinja needs some kind of attack rather than just sitting there being annoying. Aerial Ace never misses - and will also KO another Shedinja if you end up in a Shedinja on Shedinja battle
! Dig gets Shedinja out of the way for a turn, possibly away from a Fire-type - and unlike most other pkmn, Shedinja doesn't have to fear someone using Earthquake or Magnitude while it's in the ground for double damage because it's not affected by Ground-type moves.
I really Do Not Get why Shedinja is able to learn Sandstorm. That's a Rock-type move & Super effective against Bug-types. Shedinja suicide? Isn't it
already dead?