Blue Diamond

Blue Diamond is one of the three ruling Diamonds of the Gem Homeworld, first appearing as a hologram in the episode "The Message". When Steven is imprisoned in a tower on the Gem Homeworld, Blue Diamond arrives to scold him, thinking he is Pink Diamond. However, Steven reveals that Pink Diamond faked her shattering and became Rose Quartz, leading Blue to initially remain hostile. Later, Yellow Diamond is initially hostile but eventually joins Blue and Steven against White Diamond. In "Change Your Mind", it is Blue Diamond who helps Yellow realize that deferring to White Diamond's perfectionism has made her miserable. After Blue and Yellow arrive to confront White, she immediately possesses them before they can tell her how they feel. After White is defeated, the Diamonds travel back to Earth, where Blue initially refuses to help but later agrees to help Steven heal the corrupted Gems.