Warpgale

Screeching in an unholy tongue, the Grey Seer parts
the veil of reality and draws a ravening gale of
unnatural energies forth.
Pick 1 enemy unit within 26" of the caster and
visible to them. That unit suffers D3 mortal
wounds, and any run or charge rolls for that unit
are halved until your next hero phase. If that
unit can fly, it cannot fly until your next hero
phase (in addition to having its run and charge
rolls halved).