The Following information is from http://www.ign.com/wikis/final-fantasy-15
Declaration of War is the third and final major quest of Chapter 2: No Turning Back. In this mission, Noctis and the Kingsguard will plan an attack on the blockade to open up roads into Duscae.
- Recommended Level: 8
- Reward: 600 XP
Cor will call you as you leave the tomb with another task: The empire has begun building some bases, and if they build this latest one, you won’t be able to get anywhere near the other tombs in the West. First thing’s first – find Monica and get the details for this base-burning mission.
Meet Monica at the Prarie Outpost
Heading back to the outpost (the Imperials will have vacated the area by now), speak to Monica to learn that you’ll need to take out the nearby roadblock so you can travel farther to the West. Attacking head-on isn’t wise, but there is an opening nearby, just to the South of the Norduscaen Blockade.
Head to the Norduscaen Blockade
Head out from the outpost and make your way down the road to the other side of the blockade. The way is possibly blocked by a few Anak and their calves – so make quick work of them with greatswords to sweep their legs to get the giraffe-like creatures into a vulnerable spot to take out.
You’ll meet Monica up ahead through a narrow path around the back, and she’ll inform you that Noctis will join Cor, while the rest of your team goes with Monica to create a diversion. Meet up with Cor on the other side of the narrow passage, and head through the door before turning left to find a Hi-Potion at a dead end.
Eliminate the Imperials
Stepping into the open area, you’ll spot several riflemen on a ledge above – so waste no time warp-striking into the group and cut them down before they can open fire. When they are cleared, make sure Cor has caught up before heading down the stairs into the next area where a Magitek Axemen awaits – and make use of Cor’s technique to cut him down.
Heading through the door you’ll run into a new ambush as two snipers wait on a high catwalk above – quickly warp-strike up and take them out, while having Cor attack the Axemen below before you Warp-strike in from above. After they have been dealt with, continue down the far alley and grab a Hi-Elixir before turning left.
In the next room, four snipers wait on the catwalks above while Axemen patrol the ground floor. Leave the axemen for Cor as you warp-strike the snipers and take them out – taking cover when you need to restore MP. After defeating this group, head through the far door and take a left to grab a Muscle Stimulant before moving right to the other side of the blockade to reunite with your friends. However, the job isn’t done yet, as an Imperial Officer named Loqi aims to defeat you from inside a powerful mech.
Defeat Loqi in his MAX-X Cuirass
You’ll have to deal with Loqi and a squad of Magitek Axemen, and snipers on upper platforms on both sides – so it may be worth your while to clear out the rabble before you have everyone focus on the boss here.
Quickly move into position and warp-strike the snipers out of the way, then return to your friends to eliminate the Axemen. While you do, be careful of laser sights from above – as Loqi will launch guided missiles that require you to constantly move and dodge out of their way. When you focus on Loqi himself, use your greatswords on his legs to break them and cause him to lower his main chassis so that you can hit the central cockpit with your best attacks and techniques. You can even attack his arms when they are lowered to destroy his launcher and sawblade. Defeating the mech will earn you the Circular Saw – just make sure to avoid the self-destruct explosion!
With Loqi and his blockade destroyed, you’ll be able to freely travel into Duscae, and enter the next chapter of this tale.