By crafting a Multi-weapon, you can combine two weapons of the same brand (e.g. Foursis) into one. The base weapon retains all stats, augments, and enhancements. The consumed (material) weapon does not. The base weapon gains all of the material weapon's Attacks, Photon Arts and Weapon Actions which can be used in your Weapon Palette. Make sure your Main or Sub-class can equip the weapon.