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Would I be able to buy and use the DLC from GOG and use it with a copy of OOB Pacific that I purchased from Namely, I have a physical copy of OOB Pacific (US +Japan) and a copy of morning Sun (early Japan) from Slitherine. Would I be able to buy Red Star from Gog and somehow use it with my current game from Sliterine, or do I need a copy of OOB from GOG to do so?