Cocoon is like Lindzei's gestalt mode. It'll transform back into humanoid form and start smashing everything up like Unicron.
Lightning dies and in this darkest hour Serah's necklace glows and transforms her into ... Serahling! --- Capcom. Square-Enix. Bioware. Blizzard. There was a time when these companies were spoken of with respect and admiration.
Anyways, no. Lindzei forged "a ghastly cocoon" from Gran Pulse, created fal'Cie to harvest human souls and eventually disappeared, setting in motion Barthandelus's plan to reunite with what was lost. --- "The only thing that gets me high is the musky scent of my enemy's fear.'' - Stephen Colbert http://pbskids.org/arthur/games/factsopinions/