Defeat Lavos after reviving Crono at Death Peak.
Defeat Lavos while Crono is still dead.
The Dream Project:
Start the game with New Game + and imediatly defeat Lavos in the Present or at the Ocean Palace.
The Successor of Guardia:
After rescuing Marle and coming back to the Present, defeat Lavos anytime befor you reach the Trail.
Defeat Lavos between the time when you go to the end of timewith four members in your party and befor the battle at Zenan Bridge in the Middle Ages.
After slaying Zombor, defeat Lavos befor you receive the Hero Medal from Tata.
The Unknown Past:
After receiving the Hero Medal, defeat Lavos befor the gate key is stolen in the prehistoric era.