Ah, but that is for defensive walling combinations, not combinations in general.
Just my two cents, but anyways...
I have been tinkering with some theorymon for a while, and found an excellent 3 pokemon combo in Gyarados, Magnezone, and Garchomp.
Gyarados Weaknesses - Electric and Rock.
Both Magnezone and Garchomp Resist, and Chomp is immune to Electric. Magnezone resist the Boltbeam combo, so he is safe for the most part coming in on the likes of Starmie and such, while Garchomp can come in on others who wouldn't carry ice moves or threaten Magnezone with other SE moves that Chomp would be more oriented to handle.
Magnezone - Fire, Ground, Fighting
Both Chomp and Gyara resist Fire. Dos can come in on fighting attacks, which are primarily physical, and force a switch with intimidate. Garchomp resist fire, and threatens fire types with Scarf Earthquake or Stone Edge, and for other users of a Non-STAB Fire Move, an Outrage in the face.
Garchomp - Ice, Dragon
Ice is taken care of by both Magnezone and Gyarados. Gyara is neutral, but would be the main switch-in for physical ice move users such as Weavile and Mamoswine, while threatening with Waterfall and Stone Edge. Magnezone can come in on many other HP Ice or Ice Beam users, but it is best to have another special sponge/wall. Dragon... isn't that big of a deal if it is coming from anyone other than Garchomp. It is primarily physical, so Gyarados can switch in. If special, switch in Magnezone, but be wary of fire moves, so again, it is best to have a special wall along with this trio.
I am just looking up possible counters as we speak, as I intend to use this in my next team, but I am fairly sure a special wall is crucial for this trio. Feel free to critique and offer any suggestions.
EDIT: I should have mentioned that Garchomp would be Scarfed and the Gyarados is Bulky w/ Waterfall/SE, but I am still tinkering with which Magnezone would be best. I suppose it is flexible depending on the team's needs.
