Mark of Tzeentch

You can re-roll save rolls of 1 for attacks that
target friendly Slaves to Darkness Tzeentch units
wholly within 12" of this model. In addition, if
this model is the general, each time a friendly
Slaves to Darkness Tzeentch unit wholly within
12" of this model is affected by a spell or endless
spell, you can roll a dice. If you do so, on a 5+,
ignore the effects of that spell or endless spell on
that unit.