Complex sentence: Lineage explains that Black Bolt originally released the Terrigen Cloud because something is coming for the Inhumans and they need everyone to hold it back with as many hidden bloodlines from every nation on Earth united.
Split into simpler sentences: Lineage explains that Black Bolt originally released the Terrigen Cloud because something is coming for the Inhumans and they need everyone to hold it back. As many hidden bloodlines from every nation on Earth united.