I have not really got into Gen 6 due to my work schedule but after seeing it's movepool I believe Chesnaught would make a great physical wall and has a great hidden ability in Bulletproof. This would be great for it .
EVs: 252 HP, 244 Def & 8 Atk
-Power- Up Punch
I placed Spiky Shield in the 1st slot because, it's a Protect move that dishes out damage if contact is made which is a very useful move. Pain Split is placed in the 2nd slot since this Chesnaught's only reliable source to recover HP besides holding Leftovers, which leads to placing Toxic at the 3rd which can go great with Pain Split for stalling purposes. And at the 4th slot Power-Up Punch takes it's place there just in case your opponent uses Taunt on you and you get an automatic +1 increase in Attack which can come in handy.