use the action replay cheat.
get u Pokemon to a high lvl but make sure its way higher then ur foes and u will surely to win
Id3191517953's answer Get the exp.share,give it to the Pokemon you want to level up and beat the Pokemon league but once you get it at a certain level for example i got my charizard to level 59 and then stock up on some healing supplies and a few Pokemon so if your Pokemon your trying to train faints send out the other Pokemon and heal the one that just fainted. but this might take a while but this actually worked for me. good luck! AgeOfWarMaster's answer well my way is say you just beat the electric gym and the wild Pokemon are like lvl 15 or higher put like a lvl 1-10 in fighting but before you attack hit the Pokemon button and get out your BEST Pokemon out and kill the lvl 15 or so and get like 150XP+ which will probabily lvl the low lvl Pokemon a few times
Try using rare candies on your Pokemon or keep battling the Elite 4 people to lvl up your Pokemon. Put your weakest Pokemon in front of your party, then switch it out with a stronger one once you find someone to battle, so your strong Pokemon and your weaker Pokemon both get exp points. Theres not much you could do but keep trying and find new ways to lvl up. You could go to some place with REALLY strong Pokemon, like Mt Mortar, maybe, and keep battling Pokemon until you lvl up stronger. Probably the quickest way to lvl up Pokemon is to use rare candies, but you need to find those, and that takes some time.
Get 50 Pokemon...
the quickest way is probably to get to the elite four and beat them over and over with exp. share on the Pokemon you want to level up
I'm only lvl 20 now but I got 3 lvls higher because I did the knife and spork challenges. 4000 exp for challenge 10+28000 credits
Go to a random enemy and attack him once. then walk away, by the time you get back you WILL be dead. unless your a lvl 120 and are attacking a lvl 1.
try to get your whole team to the same level.
same way you get lvl 50 pokemon. its something called TRAINING!!!
You can't Sorry People If you want to defeat the elite four the easy way you should have these pokemon : Typelosion lvl 65 or level 68 : Giratina lvl 50 : Empoleon lvl 49 : Houndoom lvl 51 : Luxray lvl 54 : Staraptor Level 54 Most of these are from pokemon platinum so try to find a person with pokemon platinum
You need a member card, wich is obtained via an Pokemon event or hack. PS i have a darkrai lvl 100 obtained that way (at lvl 50)
Every team is good you just need to watch out for your opponents Pokemon memorize there types and strategies and your good to go also i recommend making each Pokemon's level the same that way you show no sign of weakness!