So after reading through about 20 logs with a Darkrai metagame it's not looking that great. I'll post them in this thread gradually as people get eliminated (so I don't spoil their teams), but Darkrai has been a complete non-factor. I think I've only seen a small handful of KOs
It's defenses are pretty bad so it's 2hko'd by pretty much everything. I've only seen it put something to sleep then get immediately revenged by a Genesect or ScarfChomp. Or just outright destroyed by Keldeo.
Although there was one match where Scarfrai put an Adamant Excadrill to sleep, that was neat. And another surprised a Genesect with scarf HP Fire.
I'm starting to believe that Substitute is a must on Darkrai sets based on these battles I've seen. I also can't believe I haven't seen much of a Darkrai+Chandelure combo to destroy fighting types, probably because Chandelure can be such a liability since u-turn is so common
IMO, Darkrai isn't proving to be a huge factor in these matches at all. Although it's an admittedly small sample size.
NIGMAN: JRRRR IS A SHIT
NIGMAN: HO ESLE THINK IT??