Guardian is a boss in Chrono Trigger that appears in the Arris Dome in the Future.
Speed Kill Strategy[]
This is your first hard boss fight. In the beginning, use Fire Whirl on a Bit. After about two Fire Whirls, the bit should be gone. Do the same on the other Bit. Now focus all attacks on the Guardian. Soon it will countdown from 5 to 0 and then launch two more bits. Continue the process. Save MP with Chrono and Lucca.
Lavos Form[]
When the players fight Lavos, it will have the same strength as the bosses you've faced in the past. One of them is Guardian (with bits).