For those who don't know, FWG stands for Fire/Water/Grass core. This is a three-Pokémon core where at least one member has the Fire type, one has Water and one has Grass. Here's an example:
This is a common core because the combination of Fire, Water and Grass typing each in some way cover the weaknesses of each other.
Another common core is called the Fantasy Core. This consists of the Steel, Dragon and Fairy types. They are called the Fantasy core because Steel = knights, Fairy = magic, and Dragon = dragons. Here's a good example of the Fantasy Core:
As with the FWG Core, the Fantasy Core each cover each other's weaknesses.
I usually like to fit these cores onto teams. However, having both requires using up all six slots, which may or may not be problematic. As such, I want to be able condense these two cores into as few Pokémon as possible, preferably three.
Heatran is the first example I found, containing both the Fire and Steel types. Are there any other combinatioons like this? Is there more than one?
NOTE: This is for VGC (Doubles).