Weapon mods haven't felt impactful to build crafting for some time and volatile mods/ arms week has only highlighted this further. I have a few suggestions to make weapon mods more impactful. Exotic mod slots- givining each exotic a mod slot would allow for more variation and versatility within the exotic slots. Some exotics, perhaps ones crafted by a specific foundry, could have 2 mods slots as one of their exotic perks . Foundry mods - mods crafted by weapon foundries that are uniquely aligned to their weapons, perhaps offering a boost to their origin traits or a unique synergy. These could be introduced in a foundry war event, which would play off the events of renegades nicely. Variety and volatility - truly, the spice of life. Volatile mods have created some truly fun and unique build synergies, none more than last arms week. I think variants of these mods should become permanent fixtures in our tool kits. Granted the mods would need to be tuned, especially in pvp, but having weaker (yet still synergistic varients) that exist as evergreen mods with more powerful variants as volatile mods keeps that design space open for development while giving build crafting more depth. Synergies- looking at some weapons, theres spaces where synergies fall short. For example, glaives, they've been in a weird limbo where they were granted some melee synergies but not others and certain exotics and armor set bonuses just dont really work as you'd expect. So, an example of a mod that focuses on build synergy would be one that treats melee attacks at full charge as if they were powered melee, perhaps charge is used up on kill or if guard is activated.