The Technician

In Neal Asher's The Technician, the Theocracy has been dead for twenty years, and the Polity rules on Masada – but it is an order that the rebels of the Tidy Squad cannot accept, and the iconic Jeremiah Tombs is top of their hitlist.
Its secrets could mean our survival . . .
On the savage planet of Masada, one of the native aliens is spreading terror through the human population. It creates sculptures from its victims' remains, earning it its nickname: the Technician. And only Jeremiah Tombs has survived an encounter. This sent him mad, but he may have learned something key to humanity's survival – if he lives to remember it. Jeremiah was a member of a brutal regime, now deposed, and a radical sect still wants its revenge.
The Technician buried something in Jeremiah's mind about the alien Atheter, an entire race that committed suicide. However, in seeking to understand their disappearance, we may somehow be attracting the same fate. And to unlock Jeremiah's secrets, Polity operatives must keep him alive.