From July 2015 (Pre-Smokey Quartz reveal.)
"Fan idea for what Amethyst and Steven would look like fused together. They’re are fast and prefer to fight using the slingshot as a grenade launcher. Tourmaline is very self-conscious, since Rose and Amythyst formed Marquise Quartz. They are aware that their existence means that other past fusions, like Rainbow Quartz, are now gone for good. Because of this, they are reluctant to reveal themselves to the other gems and any traits that reminds them they are the wrong fusion. They are a little taller than Pearl and are willing to set aside their anxiety to rescue their fellow gems."
More fusions needed multiple legs. Just saying.