Upgrade Builder Hall to level 9
Build the O.T.T.O Hut in Builder Base
Upgrade the Cannon Cart to level 18
Upgrade the Battle Machine to level 30
Upgrade the Mega Tesla to level 9
Upgrade the Double Cannon to level 4
Complete all O.T.T.O Hut requirements
Claim the 6th Builder in the Home Village after O.T.T.O Hut is fully upgraded