The tree people were supposed to be a race that could slightly communicate with trees. But then the fountain of life came along and they became able to communicate with not only trees, but with animals too. After achieving transcendence, they became able to control plants and accelerate their growth.
Their divine ability awakened further at the titan of law stage to make them capable of creating life bonds with any living thing. This binding is pretty similar to the connection of the soul sphere between clones of Legion. But Wood elves can only bind with a single entity.
They can use that binding to assist the entity with energy, vitality, and life force. That means they can heal the entity across large distances and also prevent the entity that they bonded with from dying.
The gift of the fountain of life is a great upgrade to them and a curse to Warrogs. It enabled the tree people to gain dominion over the plane. After all, the tree people gained the help of the whole plane with their divine ability. Plants and animals helped them to fight the Warrogs. It is understandable that the Warrogs lost. They had been weakened, their paragons had been subdued, and the whole plane was against them.
That should have been the end of that story. The world war ended with a happy ending for the tree people. The problem came when some smart wood elves sought to fully utilize the capability of their bond. Instead of giving through the bind, they sought to take.
They can turn the bond against any being, either plant or animal, by enslaving that being or forcefully siphoning their life force to strengthen themselves. They didn't do that earlier before because they needed everyone but now they don't. They wanted to strengthen themselves by using the living resources of the plane.
It should have been allowed. After all, it is their right now that they are the overlords of the plane. However, the fountain of life forbade it. Anyone who siphoned life force from others would be punished. It didn't help that they couldn't hide that crime.
Any wood elf that misuses their divine in that way experiences a physical change. Their green skin turns black just like the way a green leaf dies. This change in skin color identifies someone who has used their divine ability for bad things.
As stupid as it sounds, differences in skin color were the first and greatest thing that caused a divide among the wood elves. Dark-skinned wood elves became discriminated against by the general populace. It caused hostilities to simmer in the dynamics of the interaction of the race.
Then the hostilities exploded when some dark elves banded together to kidnap the incapacitated Warrog Emperors and Executioners that were captured. The dark elves that perpetrated the act were selfish and power-hungry. But they were also weak. So they were killed by the representatives of the fountain of life. That created a spark for the hostilities to burn.
The representatives of the Fountain of Life were willing to kill members of their race to protect other races who used to kill and harm them. It made the rebellious dark elves ask accusatory questions. Is it that the dark-skinned wood elves are considered lesser than Warrogs? Or worse, the dark elves are not considered part of the wood elves anymore.
A simple kidnapping gone wrong became a hate crime, and the criminals became martyrs. The race split apart when they started choosing sides. Some sided with the fountain of life, while others sided with gaining power at all costs. It led to a civil war which the dark elves lost. The wood elves have the representatives of the fountain of life on their side and the fountain of life itself, so their victory was assured.
The dark elves lost the war and decided to retreat underground to avoid the control and authority of the fountain of life. At least, that's what the demon god told him to further convince him to head underground to hide. It could all be a lie.
Ragnarok still isn't sure the fountain of life is in the plane at all. He knows there was someone who came into the plane and helped the wood elves, but that person should have become an Origin god by now. So much time has passed since then that it seems plausible that the fountain of life could be fake.
He asked his Vampire escort. "How sure are you that the wood elves won't be able to get to me underground? It would be mighty foolish of me to go through so much effort to get here only to be disappointed."
The devil's pit has been able to repel the wood elves before, but that was before it would protect him. He is a very important entity of interest to both the demon god and the fountain of life right now. The wood elves might try everything they can to get him. And the devil's pit might not be able to handle their fervent attacks. He has paid a lot for this protection and he wants assurance for it.
"Don't you worry about your protection. No wood elf can get you in the devil's pit. They will have to go through me to do that." It stated confidently, then its tone changed into that of uncertainty, "I am not sure that I can stop that Emperor that is your pair though. The Supreme of Carnage says that she is very strong. She is the child of the plane, after all. She is the literal defense mechanism of the plane against Vampires."
The Vampire glanced at him and said meaningfully, "Your chances aren't looking good no matter how I look at it. Your stubbornness to accept what you have to become is also reducing the time you have to grow stronger. If you were to embrace your destiny now, then you might be able to match the Emperor."
He shrugged. "I think the title of child of the plane is overrated."