This is simply a boss idea for when the core is opened. Once the core is opened, I would imagine it as a bright light filling the terminal, then a weird force pulling you in, then the core would close. You would end up in the first level. I will start it now.

NOTE: This will seem very difficult, as this would essentially be the end boss of spiral knights!

Level 1: The Core: Entrance to the Core: Level Design: Unknown Passage combined with Clockworks Tunnel. 2 Arena's, 1 Monster Zone.

This starts out much like the beginning of the Unknown Passage. As soon as you step on the party button, which is redesigned and is white and black, multiple swarm portal's will spawn, teleporting in void enemies, and new Void Overtimers, which through glowing pitch forks. There are also new, more advanced, Dark Turrets, which are an evolution of the Swarm Turret. These turrets are much faster, and can fire 3 bullets in a row at random angles, all in quick succession. 15 enemies must be defeated to move on. At that point, a large swarm seed will instantly spawn, and cover the next stage of the level, which is the first monster zone. Another swarm seed will engulf the room you are in, and a single door at the top of the room. The next room is a very large square, about the size of Lord Vanaduke's chamber with 5 gates at the top, which will drop after each wave, will have 4 Dark Tureets in the center, along with a swarm seed, which has spikes covering it's center. When the swarm seed is disabled, the spikes will drop, and the turrets cannot fire. There will now be a new, and Swarm Bombies, which will constantly spawn as long as the swarm seed is active, and a Swarm Dreadnaught, which deals pure normal, and is literally a walking grim totem. The Swarm Dreadnaught is immune to all damage, as long as the swarm seed is active, and will spawn in the final wave. First wave: 5 Swarm Portals will Spawn, a random number of enemies must be defeated to move onto the next wave. (between 10-20). Second wave: Turrets and Swarm Seed Spawn, first wave's fight happens again. Third wave: Swarm Bombie Spawners along the end of the room, only thing they dont cover is the 2 doors. Swarm Bombies deal pure shadow damage, and will act like regular, instant respawners. 15-20 enemies must be defeated. Fourth wave: Spikes on swarm seed activate, swarm seed has evolved and debuffs all knights/friendly mecha knights. Bombies respawn faster, there are now 8 Swarm Portals. 20-25 enemies must be defeated to move onto the final wave. Final wave: Swarm Dreadnaught Spawns, Swarm dreadnaught is the boss of this level, his defeat opens the exit. He shares the following stats that are different then the regular dreadnaught:

He is immune to all damage while he is standing on a swarm seed.
He is like vana's mask in defense while he is not on a swarm seed.
He deals very high normal damage.
He can deal any status effect with his charge.
He has increased ressurection speed, working like a grim totem on steroids.
He can turn towards players while charging.
He has a very powerful charge attack that can be used when he is NOT on the swarm seed, and will involve him stabbing the ground, damaging all players on the field, sacrificing his defenses, and increasing the attack power of all monsters by about 1/3 of their normal attack power.

As long as he is alive infinite waves of all types of zombies, and no swarm bombies, will spawn from all spawners in the room. The Swarm Dreadnaught's defeat opens the exit to the final monster zone. This is essentially a run for your life, infinite waves of constantly spawning monsters will appear in a long passageway, with an alarm going off. This is where the true fight begins. You don't have to defeat any enemies, but an army of swarm enemies is defending the lift. As soon as all living players are on the lift, the next level will begin.

Level 2: The Core: The Seige has Begun: Level Design: Same as level 1, many gremlin bodies everywhere. 1 Death Run, 1 Arena.

This starts with a com link communication from Feron.

Feron: So, you made it into the core. What is the status?
Knight: (Tell Feron of the large swarm fortress, and the new, more powerful enemies.)
Feron: Interesting, well the signal from the core has grown stronger, and Haven is under attack! The Swarm has come to destroy us!
Knight: WHAT?! Are the strangers okay? We never meant to put them in harms way.
Feron: Yes, they are fine. But they have blocked the entrance to the arcade, and are outnumbering us a hundred to one! Anyway, we have detected a large signal that is near your current location! We believe this is a Recon Module from Alpha Squad! We need you to get to that base and see what is going on.
Knight: Yes sir, but we are met with heavy resistence! But we will not stop fighting till we reach the core!
Feron: Good luck, (knight name here), you will need it.
End Conversation.

The first part of this level is what i call a Death Run. Very similar to the middle part of the Unknown Passage. It's a large, swarm infested maze. Filled with Dark Turrets and Swarm Seeds. Multiple Swarm Portal will appear. And timed explosive blocks will block the passage in multiple locations. Many dead gremlin bodies will litter the floor. The next part is the same arena as that at the end of the first level. Then, you will reach the base, which will have a large white circle. No enemies can enter the circle. In the center will be a Alpha Squad Recon Module. It will function similar to an Echo Stone as the message it says will be showed on screen. The module will be the following:

A Recording from Euclid, Alpha Squad Leader:

If anyone is reading this, they need to get out, now. This place is evil itself. It is under the control of a very powerful being, I know this, but I don't know who this being is yet. As we get closer to the heart of this fortress the darkness grows stronger, more concentrated, and more horrible, all at the same time. We also found many gremlin's down here, who are also fighting the darkness. They are supposed to be lead by this ex crimson order member named Emberlight, who most of them call Herex. They have been leading us to Herex, where we can hopefully get some supplies, and a rest.

But there is one thing, one much more horrible thing. As we were fighting, Rulen's armor, weapons, and body began to darken. Even though Grantz freed him from the darkness before, it had already corrupted him. Rulen then started to attack Parma, and if it hadnt been for Grantz's quick reflexes, she would be dead now. We managed to descend to the next part of this horrible fortress. Hopefully Rulen will be the only one of this squad corrupted. But Parma was struck by Rulen's blackened blade. I can only hope she wont be corrupted.

Level 3: The Swarm Generator: Level Design: Same as second and first levels, more gremlin bodies appear, upon inspection they bear the logo of the Crimson Order.

In order: 1 Mini Boss, 1 Death Run, 1 Boss Fight

This will begin with dialog from Intel Agent Kora.

Kora: I can't believe I'm speaking to you again, once Feron told me about your situation you are currently in, I thought I wouldn't speak to you again. Anyway, what did you find out from the recon module?

Knight: (Tell Kora about the Recon Module)

Kora: Well, I can only hope that Euclid found a cure to that weird infection, or else I fear that Parma will be infected next. Anyway, apparently Herex is going against The Swarm, which explains all the gremlin bodies you have found. Anyway, the Core's energy signature is growing stronger. Something is happening, as we knew it would. Many earthquakes have been felt on the surface, we think that the Swarm is the brain of Cradle, if so, this will NOT be fun later on.

Knight: Indeed it won't. Anything popping up on the radar?

Kora: Other then static? Yes, the farther you go the less static we find. It appears as though there is some large, generator on your level. If you can take down the power, we can establish a more permanent link to you, and take down all this interference that we have been having. Apparently some powerful things are protecting this generator, so be prepared for a big fight! Also, we have been getting messages from the Swarm, but we can't translate them. We did get one phrase, "We are the created, and the creators. We are the brain of this world. We are the darkness that consumes all. We cannot be killed. We turn darkness into reality. The Apocrea are our servants, our slaves. We are the true leaders. Surrender now, or the suffer the same fate as your friends."

End Conversation

The first arena of this is the hardest yet. As it contains a new enemy, the Swarm Battlepod, a large, swarm infected battlepod, it bears the eye of the swarm, and is entirely black. The Swarm Battlepod will be a mini boss, and will have 4 stages, thus having 4 waves. What makes this hard, is the swarm battlepod is in the center of a swarm seed, the swarm seed will indicate the battlepods health. The room is a circular room, with many swarm portals along most of the edge. The first stage has no swarm portals, the pod is off, and there are 4 Dark Turrets, at the corners of the room. Second stage the battlepods eye opens and the 2nd stage begins. The swarm seed activates and 3 Swarm Portals open. The battlepod can launch an extremely powerful laser beam that will rotate around it, or it can launch a swarm of bullets that will deal random status effects, or it can deploy an attack using the swarm seed, the Swarm Surge, it will cause the swarm seed to pulse a red energy 3 times, each one deals more dmg, and the 3rd one deploys the Death Mark on whoever it hits. All these attack deal pure normal. The 3rd stage is the same as the 1st, but there are 6 swarm portals, and the swarm seed is active and cant be hit. The 4 stage is the same as the second, except there are 9 swarm portals, and the battlepod will shoot much faster, and it has 2 sets of orbiting bullets, 1 with 4 orbs surrounding the pod, and 1 set along the edge of the room. with 8 bullets. The defeat of this stage ends the fight and allows you to progress to second Swarm Maze. The swarm seed will go away as the the battlepod explodes in a series of red explosions, the final one will send a pulse of red energy that will deactivate the swarm portals, and the turrets, and allow you to exit the room. NOTE: If you are standing next to the battlepod when the final pulse happens, you will be instantly killed, no matter how much health you have. The second swam maze is far harder, as 4 keys are placed in random blocks throughout the room, and are needed to open a "Mega Gold Door", this door will need 4 keys to open. The final room is the same room as the collector fight, with a swarm seed in the center. The final fight of this level contains the boss fight of the level. It is a large, Swarm Infected Version of the collector. It has mostly the same attacks as the collector, except for that fact he is immune to all damage as long as he is standing on the swarm seed. And he can also launch a powerful storm of rockets at players, while making it so he can't move, and lowering his defenses. Next up is the Generator, which has a party button connected to a large battlepod shaped device. With many power cords connecting to it. Stepping on the button causes static to go from the button, through wires, to the battlepod like device, and cause it to blow up. Which can and will dmg any players without their shield up. After this the lift will activate, it can be ridden to the next level.

Level 4: The Dark Tunnel: Coming Soon!