Right, so there's a DSF core I've been working with on my semi-stall team, and it's probably the most stable core I've come up with:
Skarmory @ Leftovers
Ability: Sturdy
EVs: 216 Def / 252 HP / 40 Spd
Impish Nature
- Stealth Rock
- Brave Bird
- Whirlwind
- Roost
Ampharos-Mega @ Ampharosite
Ability: Mold Breaker
EVs: 220 HP / 208 SDef / 80 SAtk
Calm Nature
IVs: 0 Atk
- Thunderbolt
- Dragon Pulse
- Focus Blast
- Volt Switch
Clefable @ Leftovers
Ability: Magic Guard
EVs: 252 HP / 252 Def / 4 Spd
Bold Nature
IVs: 0 Atk
- Calm Mind
- Flamethrower/Knock Off
- Moonblast
- Soft-Boiled
Right, so, keep in mind this is a core that works best on semi-stall teams. The reason this core works well is the amount of defensive synergy between them is almost impeccable, with the only non-covered weakness being Ice. Excellent partners for this core are Unaware Quagsire and Eviolite Chansey. Partner it with a powerful wallbreaker and you should be set. But really, this core can handle most teams without batting an eye, and the only ones it tends to struggle against is Hyper Offense. I'll provide some replays once I have a few decent ones.
Anyway, like I said, good partners are key to this teams success. I'll list a few pokemon that work well with this core, as they create insane cores of their own in the process:
Quagsire @ Leftovers
Ability: Unaware
EVs: 252 Def / 220 HP / 36 Atk
Relaxed Nature
- Scald
- Earthquake
- Toxic
- Recover
Chansey (F) @ Eviolite
Ability: Natural Cure
EVs: 252 Def / 252 HP / 4 SDef
Bold Nature
IVs: 0 Atk
- Seismic Toss
- Heal Bell
- Wish
- Protect
Right, so, with these two additions, what do we get? Let's see:
-Dragon + Steel + Fairy, a type combo rising in popularity due to its even greater defensive synergy than the classic Fire + Water + Grass core
-SkarmBliss, or in this case, SkarmChans, the most famous defensive core of them all
-Skarm/Chans/Quag, the PREMIER semi-stall core, used by top-of-the-ladder players such as Dauude Sandstorm
I know this is just 'Good Cores,' and what I've gone off and done is made 5/6ths of a team. Sorry. But it's just too good not to share. Truly, the only thing that can muscle its way past these cores when paired up is Choice Specs Keldeo. A good answer there would to either have a bulky/faster psychic type (such as Reuniclus) or a faster flying type like Talonflame (although at full health, Mega Amph wins 1v1 every time).
And those are my thoughts for the day, hope someone finds this useful!