William

When someone uses a skill or ability near William, he takes a temporary 'imprint' of how that ability shaped reality. He can then force reality to replicate the effect. Basically, he makes a perfect copy of one single aspect of an ability. This imprint only lasts a few hours, and he can only hold one at a time, making it useful for copying things he has seen in the current situation and nothing more.

Manifesting as a metallic spear of unknown material, the World Spear is actually just a physical manifestation of William's internal World Seed. It doesn't do much of anything special, acting as a strong, sharp weapon that can be thrown, or emit bolts or waves of destructive force. While extremely strong, it is not in any way special otherwise.

William can define which direction is 'down' for anyone he is touching, or for himself, and fall in that direction. This overrides the local gravity, if any, and he can alter the gravitational pull to any value between the local gravity and Earth-normal gravity, though powerful high-gravity wells still override even this ability. It also allows him to define where the 'ground' is even if nothing is there, allowing him to cut falls short, make staircases for himself in midair, and otherwise maneuver in any direction without truly flying. Touching someone while activating this makes the effect extend to them, but only as long as he is touching them. This can be disorienting but it makes it hard to use offensively.

William's World Seed makes his body an extension of the World Tree's reality, or perhaps a pocket of resistance against it. It's hard to say. Either way, it is close to a fixed point in any given point of time and space, making it extremely tough to damage, and also lending it greater influence over the world, making it appear faster, stronger, and overall superhuman to incredible levels. He can hurl cars and move fast enough to be a blur. This reinforcement is not absolute, though. He is very high-tier in his level of strength, speed, and toughness, but very far from indestructible. He is, however, completely unaging.

Living centuries with battle has given William plenty of experience fighting, but his memory and reflexes are not as unaging as he is. Vaguely familiar with most weapons, he sticks to a narrow range to be competent in. These days, his choices are unarmed combat and the use of a spear, giving him very impressive skill in both.

With great effort, William can force a Vine to connect two Worlds. He can only form the connection between his current location and some other location he has visited in the past, and this connection cannot break the normal rules of Vines. In other words, he cannot open a Vine into an active volcano, but he could open one to a plain that is currently being flooded by a storm. He can even open these Vines to Buds, but these connections tend to wither quickly unless something else stabilizes them.

Tapping into the beliefs of living worlds, William can manifest a copy of an ancient being from their legends. This being will usually be strong, fast, and tough... but only have the 'signature' ability of its own myth, and will only be as powerful as William is able to make it with his spare energies. This can make a much weaker version of the actual being, or if the legend is great enough and the original weak, the copy may be stronger than the original. As this being is created from myths and beliefs, William has little control over the specifics, but the being is under his control. He can only manifest one of these at a time, and doing so takes enough energy that he can only make one every few days.

William has a desire to see the World Tree die, and endeavors to pull people into this cause whenever he can. He doesn't think much of normals, but anyone capable of carrying a bit of their own reality with them, or the destiny-bending people known as Harbingers, he considers useful for these goals. He will avoid conflict with people he thinks are recruitable, even declining to fight them if he thinks it is detrimental to this cause, and he will ask them to join his cause at the soonest opportunity. He can hold off until after a crisis, but he will inevitably start pestering, up until someone declares him an enemy or repeatedly tries to kill him. He is often very tone deaf as to when to request this, and his true allies really wish he'd leave recruitment to them.

William likes to know what people can do, and finds the variation in powers fascinating. He'll egg people on to use their abilities, and even with opponents will often hold off on attacking full strength just so he can see them do something new. This can get very dangerous for him and anyone around him.

If someone doesn't have an appreciable imprint upon reality, that is, capable of taking fate into their own hands, William doesn't view them as a person. The normal people in day to day life are just numbers to him. He is not a psychopath, and will take reasonable measures to save lives, but he ultimately plays the numbers game and is not at all shy about saying so. This lack of understanding leads him into obvious social blunders from time to time, as he finds no reason to keep his disdain hidden.