Easy concept to grasp!
i have thought of a really nice way to include dual weapon and i'm here to enlighten you. i have seen and played many games and just like this one, it has a basic combat play. Spiral Knights combat play is based solely on having a shield (defense), a gun, and sword ( attack power) which u all know. I'm sure the game developers wouldn't want to take on a whole new burden of creating a new combat style when they think the current one doesn't need any diversion into a new one.
so instead of creating a whole new combat style for in game dungeon fighting expeditions, add a whole new PVP line where we use double sword. Just like they have done with lock down which is a whole new combat style. that way they wont have to worry about changing in game dungeons to match for the dual wielding force power and physical attributes. So how will they do it you ask, here is my thoughts.

- Attacking/combo
What they can start with for the combat style is to make when double wielding any weapon, it would have to be the same weapon because matching different weapons together will make them have to come up a really hard combination style. i'm sure you all noticed that all weapons including guns have 1 to 3 rounds for combo. An example would be the punch gun fired once then reload, or to the sword lines like troika which only has two swings to the cutter which has swings. So instead of creating new rhythms, keep the same rhythm and just create a new combo. so for example, having double cutters on would be each step of the rhythm, you would swing both sword for that one set. so that way you can continue on attacking with three sets of swings and adding a pause at the end of the swing like it has for all weapons. for the charge attack, you would attack with both weapons, but have the same combo. it would just be little faster dealing at least not double the damage, but dealing the damage of 1 cutter would do and half more of the other cutter. i decrease the damage because dealing dual blade split concentration, and so it would also cut the damage in half of one of the swords. weaknesses of wielding double blade is obvious of having no shield and while doing the combo they would be vulnerable after finishing the combo. advantages are that they have greater attack power and greater agility when not attacking. i only say greater agility because they do not have shield and when your emphasized on attacking, you need your speed to dodge.

+ another example for the troika is still have only two swings, but one swing would swing normally and the other swing would use the momentum of the last swing to swing a much more more powerful swing which would have greater push back. charge attack would be to slam one sword which would have an effect of causing a minor ground shake causing any enemies wearing light armor in a certain radius to be stunned for 1-2 second and the second swing would have the same impact as the troika line. the weakness of dual wielding heavy blades is that they would be moving slower after they use charge attack causing them to be vulnerable, and that they do not have shield. advantages would be greater attack power, and the shock i added.

- guns
having dual wielding guns would still have the 3 shot, 2 shot, 3 shot, or 6 shot combo. what they can do for one shot weapons like the punch gun is to fire both guns at the same time then reload. charge attack the same, fires both weapons, but they will have double the damage. for two shot weapons like magnus is to fire on gun the the other each having the same attack power as if they fired two shots from each gun. for 3 shot guns like the blaster, they would fire one shot from each gun then do a double shot for the last shot then reload. for 6 shot guns like the antigua, you would fire 3 shots from each gun, i do not want to end antigua with a double shot because antigua i feel doesn't need it sense it has an even number like the magnus of 6 shots. the charge attack for antigua would be 3 shots from each and the last sot will end with fire-ring both weapons. the weaknesses dual guns is that they have no shield, when they are reloading takes longer about 1-2 sec based on the gun u have and that while fire-ring, they move a lot slower like charging the electron charge bomb. advantages is that they can move faster while not attacking, they have greater firepower and that each of there shots if comes with a status will have a greater chance of being implemented. like the cyrotech alchemer, it will have a greater chance of freezing when hit.

-Defense
now we all know going to a fight without any defense is very foolish. expecting to doge every hit and coming out without a scratch isn't something we can all achieve. so a way to add defense to dual wielding is to add something called counter. so basically its a block but a block that cannot be used repeatedly based on what type of dual wielder you are.
+ so any sword that is fast like the night blade or cutter would have one counter. swords like the flourish would have 2 counters. swords like sealed sword would have 2 counters. swords that are heavy like troika would have 3 counters.
+ guns like antigua would also have one counter. guns like blaster or autogun would have two counters. guns like the alchemer line would have 2 counters. guns like magnus or the punch gun would have 3 counters.

* so what are counters exactly? counters are the number of times you can click the defense button to interrupt or redirect an attack that is coming your way. when you interrupt that attack, you have the press it right before or before that attack finish to implement the damages on your character. so basically, its all timing. the counters will have a cool down phase just like your shield when it breaks ant it has to heal. So it would be like this, all weapons that have one counter their cool down phase would go by faster then the ones that have 2 counters and the ones that have 3 counters. all weapons that have 2 counter, their cool down phase would go by faster then the one s that have 3 counter but slower then the ones that have 1 counter. all of the weapons that have 3 counter, their cool down phase would go by slower then the ones that have 1 counter and the ones that have 2 counter. the cool down phase for the one's that have 1 counter would be 5 seconds. the one's that have 2 counter would be 6 seconds, and the ones that have 3 counter would be 7 seconds. i say this because i do not want spamming of counters. the weakness of counters though is that it can only be activated while the character isn't attacking. once you start attacking, you cannot use it until you stop attacking. also, for a defensive move for the gunners. i want to give them the ability to shoot down projectiles that are aiming to harm them. that way, they can defend against mas turrets. that would mean also they could shoot down other opponent bullets as long as u have the timing correctly.

+ well besides this new idea for the dual swords, the idea i have for the pvp, i would like to call it war or whatever doesn't matter. i call it war because i do not want this pvp to only include players. i want it to include players and monsters fighting side by side. this sounds like another pet line or a stupid tech robot following you. but it will not be like that because the monsters will not be dependent on the player movements. the monsters will act on their own and behave according to where the players assigned them to focus there attack on. if the players do not assigned them a place to attack, they will just generally attack the opposing force. each player would be assigned 1 to 3 monsters based on your prestige rank. the level of the monsters would also depend on how much heat you have accumulated on your weapons. also your base where you spawn from after you die would have some defensive turrets that shoot anyone that isn't part of that team including the opposing monsters. of course the developmental team haven't created a monster vs. monster combat system. but, they don't need to if they use the same program that they use to have the monsters attack us. the field will be the same as the field we use for pvp. the monsters should at least be wary of traps and to not deliberately walk into a furnace or an electric field. at the home base which is where you spawn from, i would like instead of having healing pads on the floor, have the healing puppy's to heal us. the more players or monsters you take down, the more focused the puppy's will give you healing as a priority. there will be 3 healing puppy's in a 6 vs. 6 battle. in a 4 vs. 4 battle their will be 2 healing puppy s at each side. i want healing puppy's because that way the players wont just jump back into the game, they will have to wait a moment like 2 - 3 seconds before they can heal. i want the pvp to stay the same, no heat, crowns or item give outs. instead, including the kromo coin we should get badges that shows our rank in the pvp. well that's it, i have more ideas, but i'm tired so see you later.

i'm only saying to make dual wielding pvp because i do not want the developers to go into changing the whole game to compensate for a new fighting style.

+ i don't think there anyway we can incorporate dual bombing, it would seem to over powered and i would not like it just cause i feel it would turn the game into something completely different.