how to defeat darkria???

If you have an action replay you can use that but if not start gathering reviver seeds and try again after you have a bunch. Hope this helps

I would start stocking up on reviver seeds, and protect Cressila if she keeps ruining it for you. Dont feel bad if you can't win in the first 5 times. I couldnt defeat dialga in 8 times so I reccomend you keep trying. P.S. I seriously also would get some doom seeds and lower down Darkrai and his group's LV.

Well i'd get as many Reviver Seeds as possible. Semming as your a Pikachu get Discharge it's extremly helpful. Take out the Rhyperior first because of it's Lightningrod then just Discharge them to death, but watch out if Darkria sends you to sleep, to avoid that use a Sleep Seed on him first so you can take out the rest while Darkria can't do a thing about it.
Good Luck!

If your Pokemon are level 100, you shouldn't have too much trouble... I beat him on the first try, and my Pokemon are level 89 and 90. As has already been said, stock up on reviver seeds. The most important thing though: Make sure you kill Darkrai first. Don't worry about the other pok�mon just yet. They may kill you and your team over and over, but that's what the reviver seeds are for. Darkrai will raise his evasiveness until you can't hit him, though. Normal moves are killer.

If your lvl 100 why don't you just evolve them. Piplup evolves to prinplup and then to empoleon not needing an item and pikachu evolves into richu with a thunderstone.they have more HP, more moves, more stats and you shold be able to pulvarise darkrie. Also take oran berrys, revivor/x-eye/sleep/totter/heal/violent seeds. Also watch out for his nightmare move, it is dreadful