Steven Universe: Purple Diamond

Here's our leading antagonist for Purple Zircon: Purple Diamond. She is a minor Diamond in the government on Homeworld (as we know that the principal Diamonds are blue, white and yellow) and she runs a construction operation, employing many Gems- including the Zircon sisters. She isn't particularly attached to any of her underlings, so she doesn't really realise when Purple Zircon is switched with another Purple Zircon.
Purple Diamond is a hard taskmaster- she thinks shattering a gem and releasing them to a quiet death for the likes of treason is too kind. Purple Zircon is frightened of what would come if Purple Diamond was to find her on Earth, leading an independent life. She despises fusion amongst different gems, even between different coloured versions of the same gem.

Purple Diamond is designed by me.
Steven Universe is by Rebecca Sugar.