- All Antiguas: RAISE the base level of damage as if they've never traded their damage for any perks.
- Glacius: DvM Undead High, this is simply because Basil recommends it as a craftable weapon in the King of Ashes mission lobby.
- Combuster: DvM Construct High, just to cover the other monster family that's weak to Elemental Damage
- Barbarous Thorn Blade and Dark Briar Barrage: DvM Beast Very High to both, given the boss lair they're associated with, and Snarbolax being viewed as a formidable apex predator among other beasts.
- Final Flourish: DvM Fiend Very High, as a direct mirror to Barbarous Thorn Blade. This would also fit Deadly Candy Poker quite well, given that it's a Winterfest-exclusive weapon, and Winerfest missions are known for their prominence of Fiends.
- Deadly Splinter Bomb: DvM Beast Very High, as a counterweight to Sun Shards which have DvM Fiends. The Beast damage bonus could arguably be higher as well, Ultra or Maximum, given that this weapon has no status effect unlike Sun Shards.
- Deadly Dark Matter Bomb: DvM Gremlin Very High/Ultra/Maximum. Just like Splinter Bomb, this is to cover the other monster family that Shocking Salt Bomb doesn't cover. And if that's not a good enough reason, killing Gremlins is mentioned at least TWICE in this bomb's crafting tree.
- Deadly Crystal Bomb: DvM Undead Very High/Ultra/Maximum. Self-explanatory, it's mentioned in the description, just like with the other Shard Bombs.
- Furious Flamberge: DvM Beast High/Medium. I feel like fire status is just a better choice against Wolvers; due to their dodge move being an instant teleport, the value from Stun's slowing effect doesn't get to fully shine.
- Fearless Rigadoon: DvM Fiends High/Medium. Devilite's dodges consist of only taking a few steps to the side, making Stun a much more reliable way to hamper their movement. On top of that, all Fiends have resistance against fire, making Flamberge a less desirable option.
- Arcana: DvM Construct AND Undead Medium. Blasters have a reputation as the generalist, all-rounder handguns that are suitable in any situation. I think it's logical to pay homage to that by giving them a slight kick in damage to BOTH monster families they're effective against. The similar logic applies for Phantamos and Riftlocker.
- Phantamos: DvM Gremlin AND Slime Medium.
- Riftlocker: DvM Beast AND Fiends Medium.
- Valiance and Leviathan Blade: DvM against Beast, Fiend, and Gremlin Low. Cobalt-line weapons are viewed as being the most basic weapons in the game, that are usually consistently reliable throughout the ENTIRE game regardless of missions, so picking proper damage bonuses for them was difficult. I eventually went off the judgement that 1) Blaster and Calibur are awarded just before Shadow of the Beast, a largely Beast themed mission. 2) Gremlins are the main opposing faction of Spiral Knights, so giving the main weapons an advantage against them feels natural, and 3) Blades of the Fallen is the mission they were awarded in. Plus, 2 other Cobalt-themed weapons (Final Flourish and Callahan) deal piercing damage, so paying some sort of homage to anti-Beast anti-Fiend damage without replacing it feels logical.
- Nitronome: DvM Construct, Undead, and Gremlin Low. Damage against Gremlins was chosen for a similar reason as stated above, and damage against Construct and Undead is added as a slight HINT at elemental damage, without replacing the bomb's current damage type, since the explosion still is a highly compressed burst of energy, qualifying it as an element.
- Volcanic Pepperbox: DvM Undead High. Many people have been suggesting to make this weapon elemental, and this is simply my solution to give it some viability in FSC without replacing the existing damage type
EDIT:
- Divine Avenger: DvM Undead (and possibly Fiend) High. This one should be obvious, Divine Avenger is very much sold as a sword intended for slaying the undead. I also think that giving it a damage bonus against FIENDS could work to keep up with its heavenly theming, despite dealing neutral damage.
My list of DvM suggestions ends here, for now, if anyone has any ideas of their own, you're more than welcome to post them in this thread with explanation for why they were chosen.