It ultimate makes sense. I'm a fan of Fusion, but I wish they made it a little better, so it would have not almost completely killed digimon.

Steven is the General of the Crystal Gems. He has Connie, Amethyst, Jasper, Rhodonite, Peridot, and Garnet with him.
Steven's digimon partners
GrappleLeomon (lion and video games) (digivolving digimon, to Platinum Saberleomon, basically completely metallic saberleomon)
Dobermon (doggie)(digivolving partner to Cereberumon Werewolf mode)
Ludomon(its a shield digimon)(digivolving partner)
Tankdramon (he saves it from deleting, ultimately befriending it)
Kyubimon (floofy fox friend)
Golemon

Few fusions for you
GrappleLeomon Golefists (fused with golemon for rock hands)
ClusterMechamon (fusion of Tankdramon as the body and head, possibly arms, GrappleLeomon and Dobermon as arms and shoulders, and Kyubimon as legs)
Primal-bamon(Platinum SaberLeomon and Cereberumon werewolf mode fusion similar to omnimon and chaosmon, Cereberumons two arms connect side by side as a single arm with his actual head becomes a crosshairs thing)

Gem fusions

Smoky Quartz ×C(Connie)

Unakite

Steven and Rhodonite fusion

Dianite