Big Mek with Kustom Force Field

While this model is leading a unit, each time a model in that unit makes a ranged attack, re-roll a Hit roll of 1.

While this model is leading a unit, models in that unit have a 5+ invulnerable save against ranged attacks. Once per battle, at the start of any phase, this model can overcharge its kustom force field. If it does, until the end of the phase, this invulnerable save is improved to 4+.