The bearer’s unit has the SMOKE keyword and you can target it with the Smokescreen Stratagem for 0CP.

In your Shooting phase, after this unit has shot, select one enemy unit hit by one or more of those attacks. Until the end of the turn, each time a friendly GENESTEALER CULTS unit makes an attack that targets that enemy unit, improve the Armour Penetration characteristic of that attack by 1. The same enemy unit can only be affected by this ability once per turn.