Complex sentence: Unfortunately his plans have to be put on hold when Tina is sent to Earth in another body; because her body eventually becomes a very dangerous weapon, he wants to use her powers against Titas to claim the throne.
Split into simpler sentences: Unfortunately his plans have to be put on hold when Tina is sent to Earth in another body; her body eventually becomes a very dangerous weapon. He wants to use her powers against Titas to claim the throne.