Return of the Founder King - Episode Ardyn DLC

Overview and tips for getting the "Return of the Founder King" achievement in Episode Ardyn DLC.

Introduction

Based on the global statistics, this achievement is the hardest/most tedious one to get in the DLC (at the time of writing this guide it sits at about 0.01%). It's definitely doable with some effort, though.

Requirements and breakdown

You need to obtain A+ Rank total. The final rank is based on the rank you obtained for each listed task. In particular, the Total Score is just one of the requirements - high score alone won't get you the achievement.
The minimum requirement is to have at least B rank in one task and A+ in all the others OR have at least A rank in two tasks and A+ in all the others.
Some tasks are easier, while others can be trickier. Damage Incurred is the hardest one and is most likely the reason you didn't get the achievement.

Note that you can get the achievement on Easy difficulty. Of course you can get it on Normal as well, but I recommend doing it on Easy on your 2nd playthrough.

Total Score

Total Score is the sum of Battle Score and Rampage Score. This one shouldn't be hard to get as long as you work on Rampage Score- I would aim to have at least 1.5 million points before heading to the final boss to get A+.
You improve Battle Score by killing enemies. You get a lot more points if you finish the enemy trough Daemonification (e.g. 2000 points vs 500 points for normal kill). Try to avoid using other skills and go straight for the 5-hit com -> daemonifcation, especially when fighting low-level guards. Killing enemies in succesion gives you a multiplier bonus, but it isn't super important. You will mostly see it when you get the 3-man ambush that leads to instant triple daemonification, so don't mess these up. Stuff like combo length, battle time, etc. don't seem to affect the Battle Score.

You improve Rampage Score by destroying various Lucis-related decorations and stuff that are spread around the city. Those consist of Banners, Signbards, Billboards, Pillars, Balloons and a few statues, but also Armored Vehicles and Megaphones on top of lampposts and roofs of buildings. All this stuff is found along the main roads of the city.
Bigger decorations net more points. Banner gets you 1000 points, while a Signboard is worth 2000. Destroying decorations in quick succession gives you 0.1 combo multiplier bonus - e.g. destroying 5 items will give a 50% score bonus for next. Try to abuse this by starting combo with destroying Banners and finishing it with Pillars and Signboards. Note that two Statues are worth 10000 points each.
I highly recommend using the sniper rifle that you get from Descension to destroy decos. In the image above if you moved a little further, you could shoot all the visible stuff without moving and rack up big combo points.
You don't need to destroy every single item on the map, but the more, the better.

Max Combo

Might seem hard but is actually very easy. You need at least 400-hit combo, but you will probably end up with higher ones without even trying. The easiest target is the first Fierce Guardian that you fight at the first amplifier. You can also get high combo when fighting Regis or Somnus, just need to be a bit careful. Go into fight with 12x Royal Arms, spam the swirling attack and you will get the A+ rank in no time.

Enemies Defeated

This should happen naturally if you go through the map doing other stuff. You need to get at least 120 for A+.

Daemonifications

Should also happen on its own. 100 enemies for A+ rank.
When fighting guards on the streets try finish them with daemonification only. Daemonification is very strong so there is no reason not to use it. Note that this counts only kills using daemonifcation - big attacks on bosses don't count.

Sectors Controlled

Destroy all amplifiers.

Undying States

When your hp reaches 0 you enter the undying state where you become a cool demonic zombie. However, this isn't cool for your rank. Zero deaths gets you A+ rank, getting one death will only get A rank. If you are playing on Easy you shouldn't be anywhere near dying anyway as long as you don't decide to facetank multiple guardians. But if you are low on hp you better pop that potion. Royal Retribution (Ardyn's version of Armiger) heals you a lot as well.
The one undying state at the beginning of the game in tutorial section doesn't count.

Damage Incurred

You get A+ rank for having less than 15,000 damage total. A rank is for either below 20k or 25k.
This one is tough even on easy. The damage adds up quickly, especially from the amplifier fights that are harder and harder further on. Ardyn has over 3,000 HP when fully upgraded, so you can do the math.
So some tips and strategies:

• Save often. Always save before the big fights - the amplifiers, the battle in front of palace, and the boss fights. If things go wrong and you are not happy with how the fight went then it's better to reload and try again. It's better to try harder early on to have bigger leeway for the final boss
  
• Use items. At the shops/vending machines you find on the map you can buy stuff that boosts your offensive and defensive stats for limited time (e.g. Power EX, Mettle VX) - each costs $2,000 so sell the stuff you get from enemies and do the budgeting. Make sure to pop them at big fights when fighting multiple enemies (don't waste them on 1v1 guardians or street fights). Increasing defense will naturally reduce the damage we take, while increasing offense will let us dispatch foes more quickly - dead enemies don't deal damage after all. If you get low on hp and want to pop a potion, then perhaps the fight didn't go well and you should consider reloading.
  I haven't tried any of the hats, because they look like trash compared to Ardyn's original one.
  
• Don't forget to upgrade skills through Descension.
  
• Use Ifrit. Ifrit helps you immensely, so cast that Firaga. When fighting multiple guardians at the last 3 fights you can just circle around the field, and wait for your tech bar to fill up and then cast Firaga. If it hits it knocks the guardians into their Vulnerable state, allowing you to hack them risk-free which will usually result in their deaths. Ifrit is also great at damaging their Protect shield - this applies to Regis fight as well. Royal Guards will most likely die from him as well, but don't worry about being unable to daemonify them - you can rack those up on streets.
  
• Play carefully. This is a no-brainer, but it's better to dodge early than try to get 1 hit more and risk getting smacked. If you are replaying this then you should have picked up what attacks enemies use and act accordingly. When Regis starts swirling the weapons around him then dodge away instead of hacking him. Remember that some actions grant you invulnerability - using items, using Ifrit, Royal Retribution will nullify any damage for the duration.
  
• Do not ignore the damage coming from the high level Royal Guards. Their Katana, Crossbow, Spear and other dudes can chunk for few hundred hp, and you will encounter these a lot even in the streets so kill them quickly, but carefully. During Amplifier and Palace fights you can try using Royal Retribution if Ifrit isn't ready just to reduce the threat.
  
• Regis and Somnus fights aren't that hard, but remember to use Ifrit

Successful Strategies

These are the tutorials that have timer on the top. There are 4 of these in the beginning that deal with daemonification, summoning Ifrit, etc. Be sure not to mess up the ones in the lab - first one will tell you to daemonify 5 enemies and if you kill them normally then you will run out of guards and fail it.

Battle Time

The time you spent on battles. I believe A+ rank is below 0:50.
You are still free to destroy decorations.

[Ivy in my Heart]

This achievement is absolutely within the realms of possibility. Shame that only 0.6% of people really went for it, probably because it's the last of the DLCs. Getting it was reasonably challenging and actually pretty satisfying. The guide helped a lot!

[§єǫuєᴋʜaɴ ⚶]

yea 1.5m points sounds about right, at 1.4m it's only an A

[ShaZ]

Thank you for the tips, its helping me as I'm doing this right now

[ポラリス | Kaze]

Fantastic guide for this achievement! I managed to get it completed by following your tips and guidelines :)

[DoctorEndugu]

@JingleJam
Updated. Thanks for the info.

[LunarMelody]

The Max Combo requirement is not 350, it's 400.
Pls update this cost me a run :'(

[FrenZer]

Thx for guide, but I got B for max combo 297. Good thing everything else was on A+.

[Xenogears]

I used Cheat Engine, did not suffer.

[Blade2k9]

https://steamuserimages-a.akamaihd.net/ugc/952983568053773029/6C8D04F9095E774BDA5C5BBAAC1052ABA0BA6D9B/

thank you for this guide! it helped me to get this last achievement.
i suggest you also add in this guide, that one can buy and use the strengt, defense and magic boosters to make fights easier.

[Vento]

@DoctorEndugu
Thank you again for all of your help.