At this moment in time Darkrai's percentage rate is -22.0% so even with a level 90+ pokemon and a Golden Mask, you're only looking at maybe 10-20% chance of getting him. It would help if your team were a higher level and i too had trouble with Darkrai but i got him on my 13th try. I was amazed. I guess it just comes down too luck but it helps if your a higher level and the rank of your team. Place a Reviver Seed on the ground and get him too walk over it (and don't use it on the way down) so that you can 2-for-1 every chance, and you're good to go. o even with a level 90+ pokemon and a Golden Mask, you're only looking at maybe 10-20% chance of getting him.
credittoDukey
one life, one chance

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