remember that Ven, Terra and Aqua's story occurs be4 sora begins his journey.
and when Ven, Terra and Aqua were still 'alive', sora is just a kid. During Ven's time, he shouldn't be a Nobody or Heartless or soul. when sora turned into a heartless, Roxas appear as his nobody. but how is it link to Ven? i really dont understand.lol.