We have the Gold Saucer, we have Cloud's motorbike, we have various minions from it, paladins and dark knights probably have most of Cloud's swords at this point, we have the Strife gear, we have the Jobs and associated weapons of most FF7 characters and their limit breaks, we have chocobos, black chocobos that fly, gysahl green feeding that allows chocobos to fight by your side... many of its summons in primal form. We even have materia and Guard Scorpion. It's difficult to see what hasn't already crossed over from FF7.