So if you put a mod with five drain into a aura slot with the same polarity, you will get additional ten mod capacity. How much capacity is generated depends on the aura mod itself and on the polarity of your aura slot. Not only do those mods give really strong bonuses for yourself or your whole team, but they also generate additional capacity for your mods. Aura mods are an essential and very important part of every Warframe build.