Best intimidate user in general ... but in a format where Marshadow is king, it is difficult for him to prove himself, but nevertheless he remains playable (Look at the replays of "Chichicchi" who is doing very well with it).This is very risky but you could switch in Magic Bounce Espeon and put the Darkrai to sleep instead. Espeon can also 2hko with Dazzling Gleam if Darkrai doesn’t switch out.
Why has nobody mentioned Incineroar..... the best Intimidate user that also has U-Turn and lots of useful resists for this format...?
If you are looking for a Intimidate user, i strongly advise you Granbull coupled with Rocky Helmet or Assault Vest ... it can wreak havoc