Voltes V (1977)

Popy DX Chogokin Voltes V, 1977 Combattler's successor, sold in Japan as the Volt in Box set of five machines that combine into the full robot. Its party piece is the Voltank, a tank mode the robot never used on screen but the classic DX toy could form, and a trick the first Soul of Chogokin remake dropped until Bandai's Respect for Volt in Box version restored it. Complete boxed sets are rare and command serious money today, so this is a grail rather than a starting point.