Darkrai: I like the Poke-Power, that is used on many cards, though. You need to seperate the youre like this-you're, because otherwise your not using grammar correctly. Hypnosis shouldn't do any damage at all! It's just a move that sends a Pokemon to sleep! Also, you put 'The defending pokemon is asleep', though it should be 'The defending Pokemon is now asleep'. I totally disagree with the Dark Pulse, your kidding me with the fact you need to waste 4 energies on a 60 damage move with no effect!? You so need to fix that. Also, you need a capital 'P' for Pulse as it is still the name of something.
Mow Rotom Lv.X: A level X doesn't deserve to only have one move! They need to have Poke-Power or body aswell! Leaf Blade isn't the smartest choice to give a Lv.X, knowing it is the ONLY move and the only attacking move. Again, you need to correct your grammar so it's Leaf Blade and not leaf blade. Plus, there is no description that you have given.
Darkrai Lv.X: This card is almost useless, because it's nothing if not in play. You need to have a more specific Poke-Power and add an attack or Poke-Body to, because that card doesn't deserve to have the Retreat Cost at 3! Really, verything on that card needs improvement!
Cresselia: It's supposed to have a Capital 'C'! Poke-Power is reasonable, again, watch your grammar! You need to correct the sentence to 'Cresselia can't be effeced by any special conditions'. Confusion does get the kinda thumbs up from me, just change the description to 'This attack doesn't effect Pokemon in the way of Weakness and Resistance'. I am facepalming myself at the Run Away, please look at an actual Pokemon card with the Power of Run Away and that is a move that Cresselia will never learn!
Dialga: I agree with the damage of Dragon Claw, because that is reasonable for a move that may paralyze. But you can't just instantly Paralyze a Pokemon, so change the description to 'Flip a coin, if heads the opponent is now Paralyzed. If tails, nothing happens.' As for Roar Of Time, the thing that concerns me is the energies needed, have at least one for Multi-Energy! What makes ialga resistant to Grass? It's half Dragon and half Steel, none of which do anything but even damage to Grass types!
Giratina: Shadow Force is a pretty good move you got, just change the description to 'Flip a coin, if heads all damage from an attack done to Giratina on the next turn.' Because the current one doesn't make much sense. Add another Psychic energy for the attack, too powerful to have only two! Shadow Claw is also alright, just change the description to 'Flip a coin until you get tails, this attck does 40 damage times the number of heads'.
Worst Card: Mow Rotom Lv.X
Best Card: Giratina
I'm a bit concerned that you didn't make these, the Darkrai Lv.X has a different illustrator to the others. You also REALLY need to improve your grammar!
