How to Level Up Your Pokemon To Lv.100 in Pokemon Gen VI games?

If you have a Pokemon X/Y equip one of your Pokemon with a Lucky Egg and used Exp O-Powers and turn Exp. Share on. Go to the Pokemon League and battle Drasna first, then Wikstrom while using Exp O-Powers. Next, battle Siebold and don't used your Exp O-Powers until you faced Malva and fight the Champion Diantha next. If you want to level up a low-level Pokemon, go to Laverre City first, then buy 51 vitamins for that specific Pokemon. You can only used 10 of each kind of vitamins and 1 other kind of vitamin on it. If you want to level your Pokemon up faster then keep leveling up Exp O-Powers until it reached level 3 and keep using it. It should take you about a week to level up your Pokemon to lv.100 if you fight the Elite Four and the Champion three times a day.