The Cerberus Voyager can combine with the other Voyagers to form the Cerberios. Each head can use 3 elemental attacks from each head. Based on the magazine scans, the Cerberus Voyager will combine with the Kajiki, Chameleon, Oushi, and the Hebitsukai Voyagers respectively.
[Source: SpecialForm12 (link 2, link 3)]