O.T.T.O

O.T.T.O is the Master Builder latest invention, a new builder available on the Builder Base. once unlocked it will give you the option to have 2 builders on the builder base or six on the home base ​

Unlocking
First you will have to get builder hall 9 so you can buy the O.T.T.O hut

After that you will have to level up other buildings so that you can get your O.T.T.O hut to level 5 and then you have unlocked the O.T.T.O builder.

Usage
Once you have fully upgraded the O.T.T.O hut you can now use a second builder in the builder base or make the master bulder move to the home base giving you  an extra builder