Start of the war
Logan 3 months before the return of Natsu went back into his crystal pretending to wake up, Laxus along with his thunder trio traveled around, Laxus carried the crystal with him everywhere. The crystal was indestructible as it was made out black matter which would always heal itself if ever attacked. Logan was at the beginning was left in the castle but when Fairy tail was dissolved, Makarov with the permission of the king gave the crystal to Laxus stating that they should care for one of their own.
One day Laxus along with his companion were traveling when the crystal on his back started cracking a white light came out of it and within the light, the crystal changed into the shape of a human body Logan using Kamui had already entered the black matter reabsorbed it back into his body.
With a complete white mask covering all the hair and face till neck wearing a blue color shirt and black pants with black sports shoes, towering 6'1 Logan stood in front of Laxus and the trio who have moved away. Logan slowly opened his eyes which were revolving from a single red eye came small black marks increasing from 1 to three before the eyes going completely black then changing into beautiful sunflower pattern a huge red dot in the middle and black flower left patterns scattered around it with red lines dividing and giving a pattern of flower Patel.
Logan saw the four people in front of him stunt slowly in a low voice asked: Where is your grandfather? Were you trying to steal me?
Laxus recovering from the shock replied: No grandpa discontinued the guild, Everyone has gone their way.
Logan smiled and summoned a poach using Arc of embodiment and throw it at Laxus who caught it: Here some money for all your trouble. Tell the old man I will come back when I see there is a need for me to come.
Logan using Kamui disappeared for his place back to the guild where a broken down Guild was. Ignoring everything Logan simply walked into the hidden underground where Fairy heart was stored.
Seeing the fairy heart Logan walked straight up to it and touched it absorbing the huge magic energy residing in it when a voice came from behind him: Who are you? What are you doing here? How do you know about the Fairy heart?
Logan didn't turn around but a golden circle opened and a black colored chains bound the person speaking while slowly releasing his magical reverse which he always keep hidden. Mavis looked frightened as she couldn't estimate the limit of the magical reverse of the person who was standing in front of her. Zeref or Archnologia in front of this person looked like little children. Logan slowly extended him hand inside the Lacrima touched Mavis's body and started absorbed what was described as Infinite magic but was less than the 5 dragon god magic which Logan had already absorbed, after absorbing about 95% of the magic energy leaving only 5% for Zeref but then he saw that the magic energy was starting to be reabsorbed from the surrounding into Mavis physical body. At first Logan through about take away the crystal for himself but then he didn't want to derail the entire plotline so decided to leave the crystal and moved back a little to watch and estimate how much magic power will be reabsorbed by the Mavis's body by the time of the war after 2 hours of analysis with Hope, he concluded that the Fairy heart will be about 30% of its formal power at the time Zeref takes the power. Feeling satisfied with the result, Logan started to move out while planning his next step. Now all he need was the Zeref to hand over the key to the concept of space between time. Done with his task he looked back at Mavis who was struggling in the chains heavily breathing. Logan said in a low voice: Don't worry little one I won't wrong you and your family. You have people who cherish you soon the time for your return into the world of the living will come.
Logan disappeared from there using Kamui along with chains that went back into the golden circle.
Soon 3 month time passed away, the grand Magic festival hype passed through the entire continent meanwhile Logan went around everywhere and read through all the books as such regarding resurrection mainly but not limited to it, different ancient types of magic and such, he didn't research anything but simply uploaded all the information onto hope, as according to what he knew and have observed Anyone who challenge the boundary between life and death brought themselves the attention of Ankhseram onto them which Logan didn't want that's why he simply collected all the information without processing or analysis it yet. He wanted to absorb Acnologia and magic in space between time first before finally targeting lesser god.
Logan observing the main members through nanotech saw Natsu returning and melting the stadium of the Grand Magic festival. Soon with Lucy and happy Natsu embarked on to reform the guild. Continuing his work of collecting the books and information about Ancient magics, lost magics and laws on which Fairy laws were created and were the reason for Mavis suffering Ankhseram wrath.
Soon Makarov was recovered and the guild was reformed with the declaration of war from both sides. Members getting back and allies joining in with Fairy tail while Zeref returning to his empire and declaring the preparation of war ordering all 12 members to launch the attack.
Mavis who knew Logan or more like guessed is going to interfere in the war prepared the stagey with minimum casualties. While Zeref paid Achnologia a visit inviting him to the dragon festival.
Logan patiently watched everything, his preparations were complete with the infusion of 5 most powerful magic - Dragon God slayer which he created using dragon slayer magic and experience from the fight with Ignia, God slayer magic which he learned and upgraded from watching 4 different types of god slayer magic, Devil's lover which gave him an element less state due to which he could disregard any kind of defense used to stop his attack, Ace of Embodiment which could create anything he can imagine with the limitations of items which are prohibited by the laws of the world such as living being and lastly Copy magic which in addition to Sharingan and arc of embodiment removing all limitations regarding copying and nullifying all kind of attacks unlike August who was limited by the use of external items.
Logan also recreated his nanotech and weapons using Adamantium-Vibranium alloy which was said to be the strongest and most durable metal in Marvel universe where cosmic entity existed in preparation of the fight. His weapon of choice was his Gunbai from naruto world due to his years of experience using it while wearing a simple T-shirt and pants made out of the black matter from the Harry Potter world.
Due to the task list which the old lady gave to him in Hotel de Luna, he knew lesser gods can't directly enter the world in physical form thus, He wasn't very afraid while doing the task, he had also met death thus knew that Ankhseram didn't have complete control over the laws of death and can't directly kill him using them thus giving him a chance to fight.
The war started soon, the dragon queen using her magic displaced everyone disturbing the entire plan which Fairy tail and the allies made in the meantime seeing her plan derailed Mavis who wasn't sure when Logan would interfere and was captured by the Dragon queen who was preparing to use magic to take out the magic storied in Mavis body, using her illusion trick Mavis ran away leaving an angry Dragon queen who used her magical power to power up her entire army, making things difficult for everyone in the alliance.
Logan seeing Makarov preparing to use Fairy Law decided to join in.
Makarov seeing that the enemy forces have received a power-up decided to use Fairy law as a last mean to take down the enemy with him he joined hands started channeling the energy but suddenly 2 golden circles opened up near his feet, chains came out and wrapped around his arms sealing the magic in his arms and every part of the body the chains moved to.
Millions of Holes opened in the sky, Chains falling from them, piercing all the footsoldiers throughout the battlefield while taking all the alliance force together and gathering them in one place and throwing the 12 Spriggan other than the dragon queen which was already with Zeref at Fairy tail HQ. Everyone whether they were with the alliance or Zeref tried their best to break free but failed. Chains throw them all onto the ground and went back into the sky in golden circles. Confusing everyone
Logan calmly stepped out of his dimension wearing black shoes, white color mask which had Sharingan symbol on it made out of Arc of embodiment, while in cloths black pants and t-shirt made out Black matter in front of the Makarov who was standing in the front of the force of the alliance still chained, Logan slowly in a low voice but still audible to everyone in the alliance sending a chill to everyone: Do you wish to die old men? As far as I can remember I didn't permit you to do that.
Logan turned around looked at now standing Spriggan with Zeref in front of everyone and this time in a cold voice said: Mr. Dark Wizard Are you ready to dance?