Groundshaker Shells

Use this Stratagem in your Shooting phase,
when selecting a target for an eavy lobba.
Until the end of the phase, each time that
model makes a ranged attack, if a hit is
scored against a target that is not TITANIC and
cannot FLY, then until the start of your next
Movement phase, halve the Move characteristic
of models in the target unit and subtract 2 from
the result of Advance rolls and charge rolls made
for that unit.