I'm going to address Klinklang like I addressed BKEX. Out speed it. How do you outspeed it? Tornadus EX, Bouffalant, Ho-oh EX, Registeel EX or Benchtini. All of these Pokemon can do 60+ (Except Registeel, but I'll explain why he's on the list in a second) damage for about five or six cards (Pokemon, *DCE, Ultra Ball, Ho-oh EX, energy, Energy Switch, *Switch, *Stadium) (*Cards are special case cards) Now, 60+ damage on T1, that can Donk Klinks all day long. Ho-oh EX, for a few more cards (Supporter, Trainer that can discard two energy, Rebirth with three energy, attach for turn, switch) can donk Cobalians, same with Benchtini. Regiteel however, requires two turns to be effective and you going first, a T1 Triple Laser to three Klinks, can turn into three prizes on T2. Honestly, I think taking out three of the four Klinks would provide some breathing room, correct?
Now, I know all of this^ is theorymon and might be hard to pull off, but I've played more Darkrai Donk decks than I can remember, and I can tell you, you need more cards for a Tornadus EX donk or Bouffalant donk than you do in Ho-oh. It also seems to me that you can't play defensive against PlasmaKlang, You need to burn as many resourses and attack as hard as you can, not to KO the big basics, but the Klinks. Honestly, I don't see where you lose to PlasmaKlang if you apply early pressure.