Its best modifier is Unreal. But the weapon's firing speed will not be affected.
- When using Acid Rounds as ammo, its damage is reduced by 25%.
- Due to its uniquely low stats, it can only receive a limited range of modifiers compared to other weapons.
- Because of its speed, it achieves the best DPS when paired up with bullets that have a high base damage, such as Hyperius or Ichor Bullets, or with splitting bullets, such as Terra or Crystal Bullets.
- This weapon can be used to deal quick damage to the Dungeon Guardian, due to the fact that its DPS is relatively unaffected by the Dungeon Guardian's high defense.
- It only has minimal ammo reservation despite its absurd speed, which causes it to consume bullets at an extraordinary rate.
- This weapon performs best when used with gear that reduces enemy defense or gives armor penetration.
- Its design and name are based off of the FN P90, a real-life submachine gun that fires very rapidly.
- The P90 was originally craftable using 10 Iron/Lead Bars and 7 Cores of Eleum.