Eh... Toxic in general isn't too hot of a move, and when it's your only medium of dealing damage, it really sucks. Quite a large majority of the overused standard Pokemon shrug off Toxic as well, namely Blissey, Gengar, Gyarados, Skarmory, Magneton, Heracross, Jirachi, Metagross, Celebi, Raikou, Snorlax, Starmie, Weezing, Suicune, and many forms of Vaporeon, Sceptile, Swampert, Zapdos, and Ttar.
Blissey always carries Aroma/Bell, no exceptions, while Gengar, Skarm, Maggie, Jirachi, Metagross, and Weezing resist Toxic due to typing. Gyarados carries Taunt always, as does some DDTtars. Tyraniboah runs sub, so the only Ttar build you can touch are really special Ttar and CBTtar, both of which will kill you rather quickly. Heracross has its Guts activated and will proceed to OHKOing you and probably a large majority of your team with a multitude of moves, super effective or not. Celebi always carries either sub or heal bell, or both, while Jolteon and Raikou has sub almost 100%. Unless Raikou is running Reflect. Which isn't too common. Snorlax has Rest as well as Immunity, and Starmie has Natural Cure. Suicune almost 100% carries Rest. Vaporeon shines as a passer, and its 404 HP allows very sturdy subs, which often finds its way on Vappy. Sceptile is a classic subseeder, so unless it's running an all-out attacking set, chances are, it has sub. Swampert often runs Rest as well.
I think Shuckle looks kinda cool too. But... it's really unusable. Did I mention that it dies to at most 3 Seismic Tosses/Night Shades? =/ Those huge defenses with that HP don't really help too much. Btw, if I had to use Shuckle, I'd run:
Shuckle @ Leftovers
Bold (-Atk, +Def) 252 HP/200 Def/58 SpDef
- Toxic
- Encore/Protect/Swagger
- Rest
- Wrap
Lum really isn't worth it. I'm assuming you're using it for Rest. Don't. If you really had to Berryrest, go with Chesto. Rest rids status anyway, so might as well. But don't. Chestoresting isn't very good without Thief. Basically, Wrap something, Encore whatever it does, and switch to something to setup. For example: Wrap opponent as they switch in so they can't switch out. They think "Oh, it's Shuckle", so they Substitute, which you conveniently Encore. Now they're stuck using Substitute and can't switch due to Wrap. This is when you switch to something that requires setup, like Charizard. So they're stuck using sub as you switch to Charizard. This gives you a turn to Sub/Belly Drum/Dragon Dance/Swords Dance/Whatever as they either now switch or stuck using sub again. A Drummed Charizard really really really really hurts =). Now then, I gave a perfect scenario. That will not happen. Ever. Or rarely. There's way too much luck involved. Wrap has craptacular hit rate, Encore might run out too early, Wrap might give out too early, or they might predict what you're doing and use an attacking move. In that case, of course, you outpredict that and poison them. =) Overall useless Pokemon though.
About that 4th gen thing... After you Swagger and Power Trick, you'll be facing an opponent with doubled attack power while you yourself have no defense due to Shuckle's second-lowest-in-the-game attack (being slightly higher than Chansey's and the same as Blissey's). That's not a situation I'd like to be in, especially with Shuckle's lowest-in-the-game speed.
like shuckle so much. I wish he were usuable. I use him for fun.