Is Ventus both Sora and Roxas

After Ventus was nearly destroyed by Vanitas, his heart was descended into darkness. It was found by a young sora, who took in the heart. Sora is not Ventus, but because of the bond they share, his nobody looks more like ventus than himself. Kairi was also bonded with aqua, and her nobody has young features of her. Riku is bonded with terra, but doesn't appear to have a nobody yet.