To forever hold

Once upon a time there were two stars said to give birth to a child, a child said to be normal in every way possible along with its offsprings. But one other star didn't like that, she also gave birth to a child, said to be opposite of its "twin" as they called it. It was said that the children were made to be enemies, but what would happen if one of them catches not so healthy feelings for the other.
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The art is not mine, all credit goes to the respectful artists.