Change Comes for Prospero
This gaming supplement for Warhammer: The Horus Heresy details the involvement of the Legio Custodes in the Burning of Prospero, where they would battle not only the Legiones Astartes, but also daemonic forces conjured in the depths of Tizca. In addition to detailed background and a new Unit for the Custodians, an Army List is presented which allows players to field the Daemons of Tzeentch in the Horus Heresy for the first time.
This 48-page softcover supplement contains:

In-depth Lore: Detailed background on the Custodians role in the Burning of Prospero, and of the elements of the Legio Custodes which joined the Censure Host.
Additional Mission: A full Historical Mission that allows players to recreate the Fall of the Domus Tenebri which pitted the Daemons of Tzeentch against the Emperors Custodians.
Daemons of Tzeentch Army List: A full Army List for the Daemons of Tzeentch including a new Psychic Discipline and rules which allow these Units to be included in Thousand Sons Armies.
Unit Profiles: Additional rules for a new Adjutorum Sodality unit for the Legio Custodes, and 2 new cohorts for the Solar Auxilia.

You will need the Warhammer: The Horus HeresyAge of Darkness Rulebook, Liber Custodes, Liber Hereticus, and Liber Auxilia, all available separately, to make full use of this gaming supplement.