The Perfect Saiyan form, Mega Saiyan is achieved after reaching the goal of Super Saiyan God. After reaching Super Saiyan God, it is easier to power up to Mega Saiyan than it is to re-power up to Super Saiyan God and it has extreme power. Goku was the first to achieve this goal. The power is so extreme that it can rip the universe apart if the user cannot control the immortal energy within his/her body. While in this form, the user is almost completely immortal and have no chance of being defeated easily. Mega Saiyan is first seen in the Immortal Frieza Saga.