IMO, Chesnaught's typing, stats, etc. means that it is outclassed on both the defensive and offensive side for OU. I'm expecting this guy to go UU and fit in comfortably (it checks many sweepers, both physical and special, with its fantastic bulk). Chesnaught's only niche is countering most in game Gengar, provided that they run Sludge Bomb instead of Sludge Wave. Also, in this stage of the metagame, most people run Sludge Bomb instead of Sludge Wave on their Gengar, but in the future, I'm expecting to see more of the latter. It's a gimmicky OU mon, but here are potential sets that can work in both UU (if it gets put there) and OU.
Chesnaught @ Leftovers
Bulletproof
252 HP / 252 Def / 4 SDef
Impish Nature
Spikes
Leech Seed
Spiky Shield/Taunt
Roar
It's a pretty standard physically defensive set, but it's outclassed a majority of the time by Ferrothorn. However, what makes this Chesnaught different from Ferro is its ability to phaze out things that try to switch in on it/shuffle the opponents team. Leech Seed and Spiky Shield provide moderate recovery, passive damage, and scout Choice-locked opponents.
This set is best suited for bulky offense/stall teams. Keep in mind that this set can't take powerful banded physical attacks, such as Adamant Chioce Banded Terrakion's CC and banded Outrages from the likes of Haxorus and Kyurem-B. For that reason, partners like Gliscor and Togekiss are appreciated.
You can run a specially defensive set with the same moves as listed above, but the physically defensive set typically works out better.
Chesnaught @ Leftovers
Bulletproof
252 HP / 252 Def / 4 SDef
Impish Nature
Spikes
Leech Seed
Spiky Shield/Taunt
Roar
It's a pretty standard physically defensive set, but it's outclassed a majority of the time by Ferrothorn. However, what makes this Chesnaught different from Ferro is its ability to phaze out things that try to switch in on it/shuffle the opponents team. Leech Seed and Spiky Shield provide moderate recovery, passive damage, and scout Choice-locked opponents.
This set is best suited for bulky offense/stall teams. Keep in mind that this set can't take powerful banded physical attacks, such as Adamant Chioce Banded Terrakion's CC and banded Outrages from the likes of Haxorus and Kyurem-B. For that reason, partners like Gliscor and Togekiss are appreciated.
You can run a specially defensive set with the same moves as listed above, but the physically defensive set typically works out better.