Usync is a pipeline tool that connects Blender to Unreal Engine, allowing users to transfer levels, static meshes, characters, animations, and caches. It supports synchronizing level blockouts and replacing them with final assets, transferring instanced meshes and Blueprints. The tool handles static meshes with _UCX collision support, character skeletons, and object transform or vertex animation caches. It also includes basic material and texture synchronization, along with a library of assets for whitebox level design. Users can access these features through dedicated pie menus and right-click context menus.