The Infiltrator ability allows a Pokémon's attacks to bypass protective screens such as Reflect, Light Screen, and Aurora Veil. This means any damage reduction provided by these moves is completely ignored by Infiltrator users, allowing them to deal full damage. This interaction directly negates a core defensive strategy, forcing opponents to re-evaluate their positioning and significantly weakening their intended game plan. It effectively transforms their 'safe' setup turn into a vulnerable opening for your team, allowing you to sustain offensive pressure.