Namco x Capcom introduced Reiji and Xiaomu.
Project X Zone is basically Namco x Capcom 2 - it had Reiji and Xiamou but also new characters Kogoro and Mii.

ALso in Project X Zone, were Haken Browning and Kaguya Nanbu, the alternate-universe versions of SRW OG's excellen and kyosuke from SRWOG: Endless Frontier. Note this isn't just a cameo but canonically the same characters dimension hopping

The same Haken Browning also shows up in SRW OG: Moon Dwellers, again canonically the same entity as the one in SRWOGEF

the SRW OG main universe also includes Gilliam, who in all his appearances is *also* the same character, not just alternate versions of the same character. He sshows up in SRW IV, Srw F, and 30.