The final 6 waves

[m3g4nsl4wnord3r]

My team was composed of 2 tacticals with Melta guns, and 2 melees with the Demon maul. You will want the perks for damage and absolutely want to run stims on your melee players, at the very least to get you to cover or to get an over shield back. 

I recently finished this and our team really had a rough go at finishing Chaos Unleashed. Wave 16 is pretty standard nothing of interest to note. Wave 17 is a capture round. The capture point is on the opposite side of the map from spawn. Remember this area, you will be using it to your advantage for massive hordes and large non boss enemies. The fences on both sides. Only enemies that shoot really hit you near these. Grenades can drop near here so be careful, but spam stun behind the fences close to the center of the map as needed. The crowds will get caught and you can take out enemies very easily. Right before the capture about 4-5 space marines will spawn. Figure out which side is closer and kill them first. Then race over to help with the other side. The rest of this wave is fairly tame. Wave 18 is where things heat up a bit. Exploding runners first and then plenty of red melee enemies. Use the stun to block the groups from entering your hideout,  after the initial large group other enemy types will spawn. Take out the enemies with grenade launchers with your guns and call out sides with shielded enemies and or melee enemies. Use the stun lock technique on either side when needed. Once you are nearing the end of the wave, there will be large melee enemies that spawn first the left and then on the right. You can stun them the same way but you need to be on it before they run across your platform. If you survive you’re on your way to wave 19. 
this wave has 2 capture points. My team focused 3 people in the middle and one gunner on the side. This funnels a few enemies to the bottom capture point, keeps just enough away from the middle to make it manageable. Trust me, it was kind of a crap shoot on this wave before we started splitting up. Once we split, we found it works very well. You will finish the middle point first and as soon as it captures, jump down to help your lonely teammate. Let’s talk about what you’re going to encounter, in the middle a large enemy with an axe appears at your spawn point. Call out what side he’s running. Your melees want to stun and kill this enemy asap. You’ll have regular melees and a few gunning enemies to deal with. Another 2 large axe wielding enemies will spawn before you finish the capture point. Once it’s done run down the stairs to help your mate. Another large enemy or two will push you by the time you get the point captured. Once it’s done run to the area you can stun lock enemy’s at. There shouldn’t be a lot left, but just get your bearings. Grab ammo and clean up the remaining enemies while you run towards the spawn area. You will be hiding behind the 3 pipes and stun locking everything that comes up the staircase on the left hand side. Melees need to run staircase to staircase, and gunners stay on the two edge pipes to take out enemies in the middle of the map and call out which staircases require the most attention. Wave 20 is a lot of Space Marines. Primarily they will come up the left staircase. You want to stun lock them at the corner of the top of the stairs so the gunner there can Melta gun them, or your second melee can stun them again. After the first initial wave, some more advanced space marines will spawn. Plasma guns and snipers will keep you behind cover and it will sometimes push your team into the corner where you spawn. Take out those enemies as quickly as you can, and watch for Space marines that just want to push. Melee and stun them to death quickly. Eventually 5-6 space marines with hammers spawn. They will push and you need to stun lock them on the stairs, or back up towards spawn but stun lock them as much as possible. The last of the riffraff can be whittled down pretty easily. Focus the snipers and the plasma gunners. Once you clear this wave grab whatever ammo anyone needs. Wave 21 starts with 1 boss Mech. There are mini waves that spawn at 75%, 50%, 25% and 10% left.  You can run away from the shots of this mech fairly easily, but stay behind cover as much as you can. I do not recall all of the specific spawns in this wave, but I will do my best to describe the best method to survive. Boss enemies should be taken out by melee players. One teammate should be down at the bottom of the stairs against the horizontal pipe. The boss mech will find his way into that area with some baiting, while he walks out hit him a few times. When he is in that area, stay against the horizontal pipe. He can fire his gun, but it goes into that pipe instead of hitting you. Everyone else needs to maintain cover. That’s the general gist of taking them out. There’s a lot of them that will spawn overall. After taking out 1 and getting the next close to on fire the first sets of enemies will spawn in. Get up to the top of the stairs. Enemies will spawn near the left stairwell, and other enemies will run up the right, where you just took out the Mech. Stun/ melee and shoot everything that comes your way. Clean up enemies and don’t forget about the enemies near your stun lock platform on the opposite side of the map. Clean them all up, and then focus on the mech, or mechs. The enemy spawns are cumulative, so if both mechs are on fire and close to death, you can spawn the next batch without killing mechs. The next spawn will include the running bombs. Callouts by the gunner so the melee players don’t try to stun them and blow themselves up helps greatly. Stun some enemies on the stairs, block up the works and have the gunner take out the running bombs. If you ever get overwhelmed, start moving clockwise towards the stun lock platform. Once you get to the stairwell before going down towards that platform try to holdout there. The mechs can shoot down towards the area in the middle. Just know where the mechs are, and if you need to get to the stun lock platform, go all at once. There will be 4 bombarders on the platform, but they can be taken out pretty easily with focus. If you have a group behind you while you move to that platform, kill the enemies to retake the area for yourselves. Then get to the railing and stun lock everything that was trying to follow you.  There will be some trash mobs in the middle to take out in the end but you’ll be moving back to spawn afterwards to kill mechs and prepare for the next spawns. The next strategy will be have the gunner players close to the corner where you spawn, while the melees slowly take out mechs. As soon as the next spawn of enemies happens melees run to meet the gunners. Focus on bomb runners in the melee players way and start to take down the big enemies that spawn with clubs or axes. If you have too much to deal with, run clockwise towards, you guessed it, the staircase before stun lock platform. Gather yourselves and regain a shield, and bash the enemies off your turf. Immediately after killing them, run back to the railing and just stun lock the train of everything that wants you dead. Once you’ve succeeded, run back to spawn and setup for mech killing and gunners at the ready for the next spawn of large guys with clubs/ axes, and running bombs. Same strategy for the next spawn as well. If anyone dies, try to stay near spawn before rushing over to old faithful stun lock platform. Just use comms effectively and run as a team to keep your shields up together. Always take out running bombs and then stun and kill melee enemies quick or stun them to push by them. 
Once you wipe the sweat off your brow after stunning and killing all the big enemies, you’ve practiced killing the Mechs countless times now, it’s time to finish this. The mechs are the last things alive. 
I know this has been super long winded, maybe some things can be better explained, it can absolutely be discussed under this post. I hope this skeleton I’ve laid out at least can be somewhat helpful. Good luck with your run. 

[Fat_Pie123]

The only part that I found to be genuinely difficult was Wave 21. The way the Nobs spawn right up your ass is just total bullshit. I actually found the Lascannon to be a fairly good weapon for blasting the heavier enemies; it's worth a try if you find the Melta Gun isn't working for you, and it can be fired at close range without aiming. Ammunition Stores and Artificer Armour or Iron Halo are also extremely helpful, especially since ammo is fairly limited. I've heard that Feel No Pain is also handy, but I never used it.

 

As you've stated, timing the Killa Kan kills is vital, otherwise you just get bum rushed. Once all the other enemies are gone, you can then simply dodge in and out of cover while firing, since the Kans make for a huge target.

 

Fandom's Space Marine Wiki also has a good summary of what to expect, with a handy map too:

 

https://spacemarine.fandom.com/wiki/Chaos_Unleashed

 

https://static.wikia.nocookie.net/spacemarine/images/b/bb/Chaos_unleashed_final_arena_map.jpg/revision/latest?cb=20120507215336

 

Personally, I found sections A and D to be the best spots to hang around, but you need at least one person to back you up, and when the spawnrape starts, you need to haul your ass back towards section G while keeping up a constant rate of fire. There are also some occasions when it might be better to keep firing and risk death rather than constantly try to stay alive; there were some moments when I ended up getting surrounded where it would probably have been better for me to stand my ground and take as many enemies down as possible rather than running around trying to regenerate my shield, which usually just ended in me getting killed and wasting time. It depends on the situation and how many extra lives your team has; IME, you will always lose a few of them, but they can be restored quite easily as long as you don't get overwhelmed.

 

I also experienced at least one crash and a brief issue with connecting to a game, just FYI. For the most part, the MP is stable, but having to start all over again is not a great experience.

Edited June 30 by Fat_Pie123

[GeminiEntity]

I completed it a second time with a different group of people. Just to add on to everything else said.

 

Pick what class you are best with at staying alive and getting kills. It's no good to pick a class you struggle with in either form. This second time my group had 2 havoc, 1 tactical, and 1 raptor. That setup we had one close call during wave 21, but we all were alive at the end and in control overall.

 

We usually started at A and D and then ran for B going clockwise while taking out dogs first and then big enemies. B is the best safe spot once the enemies are cleared out or leave. It has the best protection from the Kans so you don't have to worry about them picking at your health while you dodge and shoot enemies. Plus, when you start at A and D and then go to B, the enemies will all be coming at you from one direction and you can just unload everything you got. One of the spawns we even started at B and cleared out the enemies right away and stayed there the whole time, but you need to kill them quickly otherwise you will get overrun by the time other enemies come.