>>39964867Theory:
Arceus was trying to banish Giratina for it destructive behavior three times, and at last it succeeded. When it failed for the first time, it recreated whole universe with creation of Iron Plate and Dread Plate, which gave him power over Ghost and Dragon creature, but it wasn't enough, hence it tried for the third time, and that's how Pixie Plate was created. Thanks to immunity from Dragon, it finally imprisoned Giratina.
