Rive Shindou is Chrono Shindou's father and Mikuru Shindou's elder brother.

He's also one of the co-founder of FIVA and the mysterious clan Gear Chronicle after some circumstances.

Rive, Shin Nitta and Mark Whiting once formed a Vanguard team known as Team Nippon.

When he was with Team Nippon, he used a Tachikaze deck focused on the skill Engorge. It is possible his avatar is Emperor Dragon, Gaia Emperor.

(Source: Cardfight!! Vanguard Wiki)