Supreme Capsules are what you should not post about on reddit. It's one of the Capsules obtainable in the game and can be claimed as a Free Capsule or as a reward from events. And along with the Epic Capsule, it is one of 2 that appear as offers, it costs 750 Gold. And like the Epic Capsule it appears every fourth week, with a two week offset from the Epic Capsule. It rewards a random Supreme Researcher.