This was created as part of an in-club competition.
A full-scratch build incorporating my own original elements of the Giant Cross Heavy Machine Gun (not sure if that's the official name...).
The chest and front armor were reshaped using putty, based on the Prometheus Gundam.
The arm and leg armor and frame parts were reshaped (also based on the Prometheus Gundam).
The Prometheus Gundam is a machine that appears in Frozen Teardrop and is like the father of the Heavyarms. It's set many years after the Endless Waltz OVA, when Trowa and Quatre reassembled a machine that had been disassembled over the course of 10 years, so if

MG Prometheus Gundam Patchwork Arms | モップ's Gunpla works