What are the names of the skulduggery pleasant trilogies?

The Skulduggery Pleasants are split into 3 trilodgys. To be fair, the third trilodgy is still in the process of being made. But here they are :

The Faceless Ones trilodgy

Skulduggery Pleasant

Skulduggery Pleasant - Playing with fire

Skulduggery Pleasant - The Faceless Ones

The Necromancer Trilodgy

Skulduggery Pleasant - Dark Days

Skulduggery Pleasant - Mortal Coil

Skulduggery Pleasant - Death Bringer

Then there's the Darquess trilodgy, but it hasn't been published yet.