Chaos Familiar

Use this Stratagem at the start of your Psychic
phase. Select a Thousand Sons Psyker from your
army. That model can replace a single psychic
power with a power of your choice from the
Dark Hereticus discipline (pg 101), Discipline
of Change (pg 100) or Discipline of Tzeentch
(pg 101).
Though diminutive in stature, many lesser warp
entities whisper dark secrets that can shift the tide of
battle.