R2-D2, Loyal Astromech

{4}: Put X shield counters on target vehicle where
X is 3 minus the number of shield counters on it.
That vehicle has "whenever this vehicle is dealt
damage instead remove that number of shield
counters then if there are no shield counters on
this vehicle deal the damage to this vehicle."
if it does not already.
{3}: Remove all damage from target vehicle. (If the damage is enough to kill it, it still dies.)