Here is a rather nice Defensive Core that is becoming quite common on stall teams and that I have been using for ages
Aromatisse @ Leftovers
Ability: Aroma Veil
EVs: 252 HP / 252 Def / 4 SpA
Relaxed Nature
IVs: 0 Atk / 0 Spe
- Moonblast
- Wish
- Protect
- Aromatherapy
Blissey @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Seismic Toss
- Wish
- Protect / Soft-Boiled
- Stealth Rock / Toxic
This core basically single handedly checks every mon in the tier without attack investment or a boosting move and more, making it an excellent addition for most stall teams. Blissey is already a god at walling the good majority of the tiers special attackers, but struggles a lot with Physical Fighting-type, which Aromatisse handles the majority of in the tier. It also handles most mixed Hydreigon aimed at destroying Blissey and other Dragon and Dark-types. In return Blissey walls a lot of Poison-types that give Aromatisse problems. The core also gives a lot support in 2 giant wish passers to keep themselves and the team healthy way into the late game as well as good status control in Aromatherapy and Natural Cure and even SR if Blissey chooses to run it, meaning the only thing really needed to add is hazard removal and the rest of the team is free to be pretty much whatever. There are still quite a few threats though that give this core lots of trouble, notably CM Chande and Reun as well as others which the team will have to deal with, but there are still 4 team slots remaining that make this core really easy to build defensive teams with.
Aromatisse @ Leftovers
Ability: Aroma Veil
EVs: 252 HP / 252 Def / 4 SpA
Relaxed Nature
IVs: 0 Atk / 0 Spe
- Moonblast
- Wish
- Protect
- Aromatherapy
Blissey @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Seismic Toss
- Wish
- Protect / Soft-Boiled
- Stealth Rock / Toxic
This core basically single handedly checks every mon in the tier without attack investment or a boosting move and more, making it an excellent addition for most stall teams. Blissey is already a god at walling the good majority of the tiers special attackers, but struggles a lot with Physical Fighting-type, which Aromatisse handles the majority of in the tier. It also handles most mixed Hydreigon aimed at destroying Blissey and other Dragon and Dark-types. In return Blissey walls a lot of Poison-types that give Aromatisse problems. The core also gives a lot support in 2 giant wish passers to keep themselves and the team healthy way into the late game as well as good status control in Aromatherapy and Natural Cure and even SR if Blissey chooses to run it, meaning the only thing really needed to add is hazard removal and the rest of the team is free to be pretty much whatever. There are still quite a few threats though that give this core lots of trouble, notably CM Chande and Reun as well as others which the team will have to deal with, but there are still 4 team slots remaining that make this core really easy to build defensive teams with.