Warp Lightning

Pick 1 enemy unit within 13" of the caster and
visible to them. That unit suffers D3 mortal
wounds. Before making the casting roll, you can
say that this model will use its warp-power
accumulator to augment the spell. If you do so
and the casting attempt is successful and not
unbound, the spell inflicts D6 mortal wounds
instead of D3. However, if you do so and the
casting attempt fails or is unbound, this
model suffers D6 mortal wounds.