Sapphire Stagg was Simon Stagg's daughter who was in love with Rex Mason who mutated into Metamorpho.
History[]
In "Toxic", Sapphire Stagg wanted to get married to Rex Mason. On the surface her father, Simon pretended to be happy for them but in reality he was furious and tricked Mason into getting trapped in Project Metamorpho and gassed him, mutating Rex into Metamorpho.