Fool on a wire

Vagabond was traversing the forest.
Even after the end of the world, this place was quite lively. Animals and Spirits flitted through the bushes, the birds and ideas of birds were singing.
Vagabond tried to avoid any one of them that tried to look for some trouble. As of yet, that went well. He masked his spiritual signature and went around any concentrations of Spirits. This path wasn't the safest, but it gave him the best chance to reach his goal the same day. He was getting close to the clearing in the forest when all of the sounds stopped.

And then he could hear a raven cawing behind him. And then another. More and more ravens were cawing. And just like all of the sounds before them, they all stopped too.
Vagabond turned around. There was a clearing in the forest that wasn't there before. He could see three transmission towers and a powerline completely covered with crows above him. And one, giant, scorched raven hanging down before him.
"Vagabond...," spoke the crow.

Fool on a wire (or just Fool) is a spirit of hindsight, big and strong enough to possess a name. It tends to show up anywhere it wants and talk to humans. In truth, it requires those interactions to continue its existence and once all of the humans die, it probably will die or change into something else.

Manifestation

Fool on a wire always manifests itself on the powerlines. If there are no powerlines in the area, they show up, creating enough space for them in the area, connected to transmission towers, spreading from one horizon to the other. Those powerlines are usually covered with ravens, smaller spirits that follow the Fool wherever it shows up. They announce their manifestations with cawing and get quiet whenever the Fool starts to speak.
Then, the Fool itself shows up.
It takes on a form of a giant common raven (Corvus corax corax) holding on to the wires and hanging upside down.
It's covered with black, partially burned feathers. It has black eyes covered with leucoma, dark, heavy beak, and, as it is characteristic for ravens, its neck is covered with feathers forming a beard. Its wings are always open and hanging down. Its legs always clasping on the wire.
Looking at it, one can see the smoke escaping its body. There's always a smell of burning flesh and feathers surrounding it and one starts to feel the metallic taste in their mouth in its proximity.
Its entire look is the embodiment of one bad decision.
The manifestation happens within one blink of an eye, often scaring the one Fool shows itself to.

Vagabond looked at the spirit and then started to look for its chains to distinguish its species.
A Spirit of...hindsight.
He relaxed. Although other Faceless Ones met those Spirits once in a while, they've never shown any hostility.
"It wouldn't change anything," spoke the raven.
"What do you mean?"
"Four years ago..."
"Stop," interrupted him Vagabond.
"You staying with them wouldn't win the battle."
"I know! But..."
"You'd probably be dead like them right now."
"And how does knowing that help me? If you haven't noticed, it's the end of the world. Everyone died or dies."
"You can still help others."
"But they..."
"They will probably die? Yes. It will all end? Also yes. But you can help them. Take off some of their burdens. If it's their last breath, take away their suffering."
The ravens surrounding the big one started cawing again. A strong wind blew through the clearing and within one blink of an eye, the ravens, the transmission towers and powerlines all disappeared. Vagabond stood in the middle of the forest again. He knew the Spirit was right, but somehow, that pissed him off. He continued his journey before any hostile Spirit would show up.
He'll need to remember the name he saw on one of the chains.
Fool.
He laughed, "So he is like me after all."

Taboo:
All of the Spirits of hindsight share the same taboo and Fool is not an exception. No matter how much knowledge they may gather during their existence, when speaking to someone, they can never say anything their listener doesn't already know.

Personality

When talking with someone, Fool often takes on any personality it feels would be the best in helping its listener.
It can be kind and gentle, harsh and rigorous, or friendly and joking. The one persona it likes to take on the most is that of an understanding uncle-like figure.

A pacifist

Fool is strong enough to affect most of the Spirits in the area with its presence. As its main purpose is to talk with someone, it finds it rude when someone interrupts the conversation. Because of that, any Spirit that enters its area of influence has a temporary taboo placed on them. That taboo prevents them from attacking the one Fool speaks with.
The weaker spirits who break this taboo might be hurt, their manifestation might be broken or they might be outright destroyed.

A healer

Fool shows itself only to people who regret something they did lately and that regret is eating at them. It wants to give them another perspective on the issue, a perspective that will soothe their pain while still being true to what happened. If its listener doesn't want to cooperate, it will leave for now and come back at a later time.