FINAL FANTASY XV MULTIPLAYER: COMRADES

This achievement will automatically unlock as soon as you start playing the game provided you have played Comrades Update for Final Fantasy XV and unlocked the below achievement. If it does not pop immediately, it's probably because your character or glaive is not equipped with a sigil. Equip a sigil and it should unlock:

If you have not unlocked the above achievement in the FF XV Comrades DLC: Clear the nodes on the map, including the ones where you have to use a high level Chocobo, collecting 12 sigils in the process. Continue clearing nodes until you unlock the final story event in Descent into Darkness. That will make Insomnia available by your vehicle. Take the vehicle to Insomnia. Defeat Ifrit. You will be rewarded with the 13th sigil, The Father, and the achievement will unlock. A video guide at the end of this solution shows the location of the 13 nodes corresponding to all 13 sigils required for the achievement. All but one of the thirteen sigils are collected by unlocking nodes on the map. The thirteenth, The Father, is obtained as a reward for defeating Ifrit.

When you obtain twelve sigils, including the ones that have to be cleared with a high level Chocobo, a main story event will occur. Insomnia will become available as a location that you can go using your vehicle. It's the last location in the list on the second page with the 'somewhere else' locations. Take the vehicle to Insomnia and defeat Ifrit to claim The Father as the reward. This fight must be fought solo with AIs. Since the Father is the last of the 13 sigils, obtaining it unlocks the achievement.

The above is the solution in a nutshell. However, if you are finding the Ifrit battle either challenging or tedious, you probably need much more powerful weapons. In the below video, four level 120/strength 600 weapons are used.

The following is a video showing a suggested loadout and tactics against Ifrit.
Most of the damage is done by standard warp strikes converted by The Fierce Sigil into high DPS attacks. Wherever possible, Ifrit is attacked from the side and back to avoid exposure to powerful parries. One suggested approach is to remain in the center circle warp points. Use them to maneuver into an advantageous position for warp strikes. With powerful weapons and tactically aware attacks, Ifrit can be defeated quickly.

Ifrit has very strong defenses. You need high strength weapons to breach the defense threshold. If you need some pointers in how to acquire and craft weapons that are effective against Ifrit, please refer to this thread: Weapon Crafting in Comrades--Case Study: Ifrit. It describes how to make the level 120/strength 600 weapons used in the above video.

Fighting Ifrit. Once you are geared up, you can take on Ifrit. Take the vehicle to Insomnia. Before you leave for Insomnia, equip the sigil and equipment you want to use. You will not have a chance to change once you select Insomnia. Once your stats are through the roof, warp-strike in/warp out tactics are very effective. You can augment them with the sigil you choose. The Tall gives increased strength and a strength boost spell. Aerial Ace gives you increased damage with warp strikes. The Fierce has high DPS and charges up to deliver All Creation, a very powerful blast.

Note: Players have different play styles so choose the sigil that suits your play style. I have tested most of the sigils against Ifrit and, personally, recommend The Fierce because of its very high damage per second. The high frequency of attacks compensates for Ifrit's high defenses.

A cut scene precedes the fight. You will get three AI party members. They are less effective than normal AI companions and do not have any food to resurrect themselves when they die.
However, if you fail to defeat Ifrit the first time and click retry, the AI party members get food.

When you defeat Ifrit, a cut scene follows and you get The Father as a reward. Since you have picked up the other 12 royal sigils on the map by clearing nodes, you will unlock the achievement.

Video showing the location of all 13 sigils. The final location is Insomnia where the battle with Ifrit for The Father takes place:
You resume your game where you left off before you took the vehicle to Insomnia. There will be two new missions--rematches against Bahamut and Ifrit both at level 99.

Out of Darkness: Many people find Out of Darkness aggravating. It is a required mission to reveal a the Clever sigil. It is not an easy mission. One must prevent a Yojimbo and other demonic creatures from escaping. The Yojimbo will stand and fight provided he is periodically engaged. The other enemies try to escape as their first priority. If you fight with only AIs, alternate between the Yojimbo and the other enemies. Force the targeted enemy to change. Good weapons are a Dragon Whisker with Penetrator X/Penetrator X (my favorite - Dragon Tears from the final Behemoth in Double Deadeyes). Kitchen Knives III is very good as is Dragon Whisker with Lightbound (Dragon Incisor from the final Behemoth in Double Deadeyes). If you have a human partner, a very effective tactic is for one to use Omniguard and the other to use Aerial Ace or The Fierce. The player with Omniguard goes on the roof to the right. The avatar is safe but the Omniguard shield covers the path. The goal is to activate link strikes between the two players. All enemies can be killed quickly before any escape. If you continue to have difficulty, send me a PM and we can arrange to clear the mission co-op.

If you do character transfer: Achievement will pop once you start the game.

Newcomers refer to Original Post: