Warframe abilities that strip enemy Armor and/or Shields (Nekros' Terrify, Hildryn's Pillage, Xaku's Gaze, Ember's Fire Blast, etc.) all do so through percentages. As such, they all scale well as enemy levels rise and remain useful no matter how strong the enemy is.
Mag's Polarize is an exception to this. It strips a flat amount of damage (based on Ability Strength), which means it quickly becomes useless as an ability to help with damage and is inconsistent with the norm of how defense stripping works. I believe it should be changed to make it strip defenses based on a percentage to bring it in line with the abilities listed above.