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The overarching goal is to identify the unknown progenitors of both H-poor core- collapse and Calcium-Rich supernovae (SNe) by mapping the mass-loss history in the final years before explosion through the novel combination of X-ray emission and flash spectroscopy as a probe of the circumstellar environment. This coordinated observational technique is now possible with our access to the Young Supernova Experiment (YSE) a new untargeted transient survey designed to systematically discover SNe in the first days after explosion. [truncated! Please see actual data for full text]