Complex sentence: WWE created a duplicate world heavyweight championship after then-WWE Champion Brock Lesnar became exclusive to the SmackDown Brand, but this title would eventually be reabsorbed back into WWE's primary World Heavyweight Championship.
Split into simpler sentences: WWE created a duplicate world heavyweight championship after then-WWE Champion Brock Lesnar became exclusive to the SmackDown Brand. It would eventually be reabsorbed back into WWE's primary world heavyweight championship.