Decided by the last digit of your post number.
0 - Getter Emperor
1 - Getter Robo
2 - Getter Robo G
3 - Getter Robo Go
4 - Shin Robo Getter
5 - Getter Robo Āḥ
6 - Getter Saurus
7 - Shin Getter Dragon
8 - Getter in Emperor's Armada
9 - Black Getter
Double digits = Awakened Getter of the type you rolled (Example: 44 is Awakened Shin Getter). Exception being Emperor and Go. Roll 00 and you get Galaxy sized Getter Emperor. Roll 33 and get Getter Robo Go Final Version.
Reply to your first roll. This new post determines your enemy.
0 - Getter Valhalla
1 - Dinosaur Empire
2 - Oni Empire
3 - Rando's Army
4 - Getter Stolen by Enemy (reroll to determine which Getter is stolen)
5 - Invaders
6 - Gods from New Getter
7 - Berserk Prototype Getters
8 - Mass Produced Getter G
9 - Andromeda Flow Country
Doubles - Go out like Musashi against the enemy