There are 2 known ways, both need a living Dream Self.
The 1st, and best known, way is his/her Main Self has to die/be killed. At or near the time of death, he/she must be placed on his/her Quest Bed found on his/her planet.
The 2nd way is the Dream Self has to be at the center of the moon they live on, where there is also a Quest Bed. The Dream Self must then die on his/her Quest Bed.
In all cases, the dream self becomes the God Tier.
