Heh, by claiming Spawn had more of a place as a guest character than anyone else (even Link), you are admitting that your complaint on the new star-wars characters is nothing more than bias, and does not have a basis grounded in logic or fact.
Maybe there are people that think Yoda and Vader fit in the Soul Calibur universe more than anyone else (even the characters original to Soul Calibur). If anyone came into this argument claiming that, their point would be exactly as valid as the one you just presented.
Unless, of course, you actually read Spawn and realize that there has been more than one Spawn, spanning back countless years over countless dimensions, so a Spawn character within the Soul Calibur universe
could work (I didn't say that it was very plausible, just more plausible than the others).
You know what was great about the Star Wars movies? That part where Vader and Yoda happily skipped off hand in hand into the great Time Machine from Clavin and Hobbes to arrive in the Soul Calibur timeline...oh, wait, that never happened...
Vader/Yoda could fit into Eternal Champions far better than Soul Calibur. I wouldn't mind so much if they were downloadable additions that had nothing to do with the story of Soul Calibur, but once they get shoe-horned into it, that's when I take exception to it.