The wall of bricks!!

I still have the boomers... they just don't spin.

I connect the first and the second with a watery rod and place it on the ground so that it starts rolling toward the moat.

The third can chill for now.

Oh and as for the Death Note

A shinigami's Death Note is a notebook that can kill any human whose name is written in it. All Death Notes are governed by the same set of rules determining the extents and limitations of the Notes' powers.
Written rules
The human whose name is written in this note shall die.
This note will not take effect unless the writer has the subject's face in their mind when writing his/her name. Therefore, people sharing the same name will not be affected.
If the cause of death is written within 40 seconds of writing the subject's name, it will happen.
If the cause of death is not specified, the subject will simply die of a heart attack.
After writing the cause of death, the details of the death should be written in the next 6 minutes and 40 seconds.