Because of Tadashis Death Elsa, Tadashi Anna, Hiro

In Elsa s Coronation, Elsa met an inventor, her age name Tadashi and they both fell in love and became a thing while Anna met his younger brother Hiro and they had fell in love too. One day Tadashi died because of a really mysterious guy who could control things telepathically. Everyone was devistated but Elsa was more devastated and crushed than everyone and she was losing control of herself. Anna tried to talk her out of it but it failed and Elsa strucked her with her Ice powers. Hiro saw when Anna turned