Complex sentence: Before returning to 1992, the Futurians secretly leave three small creatures called Dorats on Lagos Island, which are exposed to radiation from the hydrogen bomb test in 1954 and merge to become King Ghidorah, which then appears in present day Japan.
Split into simpler sentences: Before returning to 1992, the Futurians leave three small creatures called Dorats on Lagos Island, which are exposed to radiation from the hydrogen bomb test in 1954. The creatures merge to become King Ghidorah, which then appears in present day Japan.