Death Frenzy

With a snarled invocation, the Grey Seer drives its
underlings into a froth-jawed murder frenzy.
Pick 1 friendly SKAVENTIDE unit that is not a
HERO, which is wholly within 13" of the caster
and visible to them. Until your next hero phase,
when a model from that unit is slain, before it is
removed from play, it can make a pile-in move
and then attack with all of the melee weapons it
is armed with.