There were 3 main reasons why Leo was taking a seat and listening to the primal gods. First, He was completely powerless anyone of them could erase his memories and make him a servant of their again or better yet erase his existence. Second, Asuna was involved, Leo didn't care about whether he died or not but with the hope to find answers to what happened to Asuna Leo decided to listen and lastly, the gods or entity seating in front of him were not entirely simple Void was an ever-expanding vortex not willing to wait for anyone, while Death ruled and judged everyone so if they wanted to take their precious times and talk to him he felt it was much better to listen to them.
A table with tea and wine came out of nowhere in front of Leo. Death and the child drunk tea while Giant took wine for himself Leo wasn't offered any so he chose to seat quietly.
The Giant/void started talking: You as his successor were the reason we took an interest in you and were observing you. Let in begin by telling you the Story of the creation of Gods. In the beginning, there was nothing but energy, No one knows what kind of energy it was where it was held or where it originated from. The energy was is the origin of all energy Omniforce, Ki, Chakra everything. The concepts such as space-time, void death didn't exist by then over time the energy which was present everywhere due to some reason started condensing into a singular point leaving behind the space it was in thus creating the very first concept of Void, leading to my birth. The energy which was slowly condensing into a ball was anything about a simple energy force it coalesced onto itself causing destruction which tore everything such as the space it was in and such thus leading to the creation of your Master God of Destruction. The energy ball over time became smaller and smaller giving birth to the real only True entity which can be regarded as creator and ruler of everything, you human also know about him and call him One above all. One above all over time gained consciousness and started created others being the first being he created was Death, God of creation. The power who One above all ruled with was the power of love which is the true source of all form of energy everyone.
In the beginning, everything was at peace, God of destruction and God of creation worked as the two sides of a coin creating balance in everything but one day the balance changed God of creation trapped into the very primal source of One above all and created Lesser gods based on the divinity of ous indirectly trying to take over control of law on which the entire worlds of his were created on. Seeing this imbalance in the system one above all created him, God of Samsara. The god of samara was very special he had control over the matters of life and it's creation thus directly putting a restriction on the God of creation removing the concept of true immortality from the lesser god. While what happened next was the reason why the conflict between the gods started, the god of creation using the primal source of love itself started creating souls, which were then used by the lesser gods to power themselves over. Your, old human world has a concept of Greek gods whose power was based on the worship, don't you? Similarly like that. Using humans and other souls as a battery to drive more powers and enhance themself. God of destruction who at that time decided to visit the human world as a mortal saw their situation decided to wave a war on all beings. Creations were destroyed erased from their beings. Us the older primal gods were also dragged in the conflict, With his war hammer, God of destruction fought everyone. I being one of the first-ever beings had to intervene to save to reality from being erased thus an accord was created between the gods. 3 of us along with God of destruction would stay out of matters of lesser gods and won't directly affect the world laws by which individual multiverse was ruled while on lesser gods and God of creation side they won't affect the lives of common people giving them free will and removing the chains of oppression thus preventing any lesser gods from even entering into any Multiverse worlds. Do you understand so far?
Leo was quietly listening to the tale and was wondering what does all this have to do with him and why did God of destruction make him his successor when God of destruction from the story was already an immoral and one of the most powerful beings.
The giant continued: Yes this story has nothing to do with you but the next part is. You see God of destruction was one of those people who appeared cold on the outside but was warm-hearted from the inside. During his travel in the mortal world, he met a woman. He similarly loved her like you loved Asuna. Their feeling was natural and pure for each other earning the irk of one of the lesser gods of that world. God of destruction who was at that time was pretending to be a mortal seal all his powers and lived a simple life with the love of his life, what can guess what happened next can't you?
Leo: The lesser god took away his love?
The giant smiling: Yes when one day God of destruction was away working, the lesser god along with his worshipers abducted the mortal girl raped and killed her. God of destruction who upon his return wasn't able to find her thus released his divinity and rushed into the world of lesser gods.
Death started talking at this point: I didn't know the identity of the women nor her connection to the God of destruction put her in the cycle of reincarnation. By the time God of destruction came forth to claim her soul she was already gone, everything about her was destroyed and erased. Angry over himself and everything God of destruction started the war.
The young boy: The war went on for many years, void only managed to stop the god of destruction by using her reality being erased fact as the argument. Thus finally ending the war.
The giant: This is where you come in. Your soul was created by the god of samsara on a whip and request of a lesser god Gaia. With the blessing given to you, many of the lesser gods turned their eyes toward you because you could directly involve and change the world for them thus making you an exception to the balance rule which was settled but in your very first world lesser god found you to be problematic, you were willing to love only one being Asuna and live with her. You weren't interested in power or conquering other beauties. You were loyal pure and most importantly a person who knew what is most precious to you. The lesser gods who were hoping for you to do their deed didn't like that, thus they started enforcing more world law into your world thus indirectly influencing yourself. At fast they thought you would leave the world after Asuna was death but you were considering living in the digital world of your to be with Asuna. They saw their plan is failing and left you along. But Asuna surprised everyone she forced you to move on and let her die. With her death, the pathway to control you opened up. Then they started giving you missions controlling your actions indirectly. Have you ever considered why Hermione Granger from Harry Potter world who was in love with you would kiss Ron? Let me answer this for you, Lesser gods. They didn't want you to tie down with her and move on so they little by little in 3 years you left her along changed influenced her. Thus making you move on from that world too.
Leo hearing this was a stunt and started thinking he in Harry potter world had Veela bloodline while also many factors which should have made it impossible for Ron to do anything with Hermione only a dream, He after thinking a bit realized that he hadn't thought about it. He at that time had already given up on Hermione and just moved on without paying much attention to this.
Void started talking again: At first, we were uncertain whether or not about lesser gods influencing you thus decided to test it, death here went and gave you a task to collect his artifacts which he had left behind in the world. Which was the only reason you went to this world? After seeing the outcome with Hermione we all were certain of the involvement of the lesser god and their plan to control you. So God of destruction who seeing what happened with his love happened to you decided to meet you and test you. He went into the mortal world of fairy tail and started observing you. And finally decided to teach you which was surprising to all of us. He made you his successor and left behind his inheritance for you. But that's why the story gets complicated. The lesser gods were already eyeing you and when they saw you meeting the God of destruction they decided to escalate their plans thus when you completed all the tasks of the world Dragon God gave you a new one. To kill all the dragons in any form. Yourself should know that the task was idiotic you could kill everyone on the planet easily much less the dragon slayers and such. But the reward which you got was Huge. Devil's lover magic which God of destruction has taught you, lesser gods wanted nothing but to stop you from using it any further but couldn't possibly deny your wish as it would seem suspicious decided to change your wish somehow, thus dragon god in addition to your wish of Devil's lover also gave you his purest bloodline. Dragon God's bloodline is one of the most precious things in the entire lesser gods domain so why would he give you something so important for free? It was to imprint your very soul itself. Do you remember the time you used the dragon god's bloodline in the one-piece world? The pain wasn't due to your bloodline changing or such but due to dragon god's blood imprinting the slave seal onto your very soul itself. The seal was in such a form that it would only create a small portion of the actual seal each time you use the Dragon god's bloodline coin. After 4 worlds you would have been under his direct control as a puppet, doing anything he asks of you thus the perfect variable.
Leo listened to everything too much information was given to him, he couldn't believe he was also made into a puppet from being a Janitor to the very people who have taken away his Asuna from him.
Death: Seeing the seal we were decided to intervene before it was too late, it wasn't because we liked it or so but because God of destruction had asked us too. We using our divinity started modifying the heavenly tribunal little by little after you had completed your task we used that modified tribunal lighting and destroyed the seal which was engraved into your very soul itself. After which you were brought here. Do you understand everything now?