[@Shiny Keldeo]

Funny thing is, that Dark types are not "resistant" to Psychic moves. They are Immune. It have no effect on them unless Miracle Eye removes their immunity xD. 

And then its normally effective at 1x damage xD. 

Its like a Fairy type being immune to Dragon type moves.

A Steel type being Immune to poison attacks. 

Etc. 

Unless he have like a 'Type' Buldozer emera effect in PMD. Which makes move's ignore immunities, resistances and work at full effect at all times.

But wth, Mystery effects for the win xD