The Black Aurem is very fragile, having the same hardness as logs. This, combined with the creeper's ability to explode while trapped by the Aurem if a player is in range, makes it a bad idea to stand near the Aurem at night. It is best to keep one's distance from the Aurem once it's built, in order to prevent the Aurem from being destroyed by an errant Creeper. As shown in the image to the left, the Black Aurem has a range of roughly 10 blocks.
In order to work, The Black Aurem must be able to lift mobs slightly above itself. While the Aurem only occupies a two-block space, make sure that the two blocks above it are also free.
The first level of increased efficiency is achieved by drawing a square around the Aurem with wizard's chalk, occupying all eight blocks in the 3x3 ring around the Aurem. The second level is achieved by constructing four two-block-high pillars of Nether Bricks at the corners of the chalk square, and placing a cap on each pillar of gold blocks, diamond blocks, or Chimerite Blocks. All four caps must be the same. For maximum efficiency, Chimerite Blocks should be used. An example of a Black Aurem with both upgrades applied is provided to the left. Note that the Aurem itself occupies the space in the center of the chalk square.