First off, I feel there's too much potential in other third party series for Richter to be the only third party echo. We could have...
I don't know much about Metal Gear or FF7, but I do know just enough about them to know how ironic it would be to have either of the the last two as echo fighters to their respective characters.
- Shadow or Metal Sonic (I'd prefer the latter, but the former's got the popularity and is already rumored. Plus, Shadow isn't that similar and does have potential for his own moveset, but I'm pretty sure the same can be said for Dark Samus)
- Prototype Man (he may be a part of Mega Man's final smash now, but technically Samus is part of Ridley's final smash and she's still her own character. His final smash, since Chrom has established that those can be different, could be him firing a blast like the one he broke King's shield with)
- Ms. Pac-Man (this one feels like a no-brainer to me, but then again so does making Mario's 8-bit SMB1 colors one of his costumes and they still haven't done that)
- Ken Masters (and just like Shadow, there's already rumors)
- Big Boss
- Zack Fair (although he's made exactly one appearance on a Nintendo console from what my research can gather. Boy I'd hate to be wrong about that after pointing out Richter's other such appearances to VorvenDorven)
I don't know much about Metal Gear or FF7, but I do know just enough about them to know how ironic it would be to have either of the the last two as echo fighters to their respective characters.