This page explains how to obtain Ending 5: “The Rebirth of Marbule” in Chrono Cross: The Radical Dreamers Edition.
How to Obtain Ending 5
To acquire this heartwarming ending, you must defeat the Time Devourer after obtaining Lynx, but before rescuing Riddel.
As usual, return to Opassa Beach and use the Time Egg at the dark-colored distortion to teleport to the final boss battle. If you need help fighting the Time Devourer, please check the dedicated page.
Although your party is somewhat limited, since you’ve lost half of your crew, it’s not too bad really. For one, you’ve got Lynx and Harle, who are Black Innates that can deal big damage to the Time Devourer with their techs/Elements.
Also, you could use Sprigg and have her Doppelgang into some busted monsters from the endgame. Heck, you could even Doppelgang into the trio from the Bend of Time; Ozzie can deal some nice damage with his standard attacks.
Thwart the Time Devourer and you’ll receive this ending. Lynx and Harle will wander around Marbule, which is in the process of being restored. Meanwhile, at the Dead Sea Ruins, a deadly confrontation awaits.
See Ending 5: The Rebirth of Marbule.