Original: The player will have to chase down Cyrus, now infatuated with the power of the before-unknown Giratina, to an eerie dimension known as the Distortion World (Yaburareta Sekai), in which Giratina has resided for countless ages.
Simplified: The player will have to chase down Cyrus, now wanting the power of the before-unknown Giratina, to an eerie dimension known as the Distortion World, in which Giratina has lived for many ages.