The Altar Diviner is the second stage of Blood Altar automation from Sanguimancy. It is a GUI-less machine with a single internal slot. Items are placed in it via right-clicking. An empty hand must be used to empty it. What makes this block so special is the fact that its internal content will be transferred to the Blood Altar only if it contains enough Life Essence, and is the right tier. It can move up to a stack of items at a time. The Altar diviner will also take items out of the Blood Altar's inventory once the crafting is done.
To work correctly, this block needs to be placed directly adjacent to the Blood Altar, as in the picture below. A tooltip was added for in-game remembrance.