In my opinion, Chansey or Groudon would be better.
Klefki is a better wall setter than carbink for prankstar priority. Araqunaid isn't much bulky. Umbreon would be better. Its weakness can be covered by florges, hawlucha and salamence. Its special bulk is good. plus it has moonlight. But its PP is low. Since you are using calm mind, dark pulse is better than last resort. Foul play is also good. I'm not sure how much good would be evasion move on slower Pokemon. And now every team keeps defog. I've never used evasion moves, wish or toxic may be better. Confuse ray isn't a good move. Because chances of hitting itself during confusion has been lowered in gen 7. Moonlight, calm mind, dark pulse and double team?/toxic or wish is good. Give it calm nature (doesn't it raise SpD?).