Origin
Arturo Cruz was an artist of part Mexican, part Egyptian descent, who was associated with the fringes of the counterculture in 1960s San Fransisco. A brilliant man whose talent was nonetheless dwarfed by his ego. After a series of failed relationships and personal meltdowns, he became increasingly dissatisfied with his life, longing for something more. And so he fell into the orbit of a group of infamous occultists who learned the dark arts with the goal of enslaving humanity. He began to dabble in magic and incorporate elements of it in his art - which is just what he wanted. The group saw the powerful potential for magic within him and led him to work on a new piece of art as part of a secret ritual, a ritual of whose true purpose he was ignorant.
Before long a group of people were gathered to finish the ritual and the painting into which Arturo had poured his heart and soul, a painting of a strange other world. The painting was made as a doorway... and something came through. Seven people died that night. They were the lucky ones. Arturo only lived because the thing he had brought across ate his eyes, hoping it would drive him into despair and suicide.
But over the course of his studies, Arturo had heard a strange rumor that seemed to offer hope. Somewhere in Mexico there stood a vast tree in the middle of the desert, invisible to the eyes of all but a few, in whose branches was a lost city whose ruler had the power to heal any injuries. He crossed the border alone and went into the desert to seek that city. For three days and three nights he waited until he heard the singing of the birds in the trees and the chanting of the city's protectors--and for one brief moment, he saw it.
The city exists to guard the remains of the Tree of Life. When it is fully healed it will bring about a new rebirth for the world, but if it is destroyed all hope for the future of humanity will be lost. Several times the Tree has been burned down but its roots have been preserved and taken elsewhere to grow a new city. Before it came to Mexico it was located in a now-sunken island off the coast of Ireland (thus the Celtic knot) and before that in Israel.
As Arturo entered into the city he was met with disappointment. Its guardian, the Mysteriarch, claimed that they could not cure him. They could only offer him wisdom. He was ready to leave until he found that the Tree of Life was threatened by the thing he had brought across. He knew that it was time, for once, to make up for his past failures. And he genuinely wanted to learn what the city had to offer. So he became an apprentice of the Mysteriarch and joined the defenders of the city.
As Apprentice he was given a seed of the Tree of Life to eat. Eating the seed gave him new eyes--literally. He could now see into other worlds, the Astral Plane, and the Beyond. It also increased his lifespan and slowed his aging considerably. But there was a cost because he could not see the normal world during the daytime. He could never return to who he was. He had become something new: Dr. Acacia.
Today he has himself become the Mysteriarch and taken on apprentices of his own. The acacia tree was the first tree identified as the "tree of life" (by the Egyptians), and this is a concept shared by many magical/spiritual traditions.
Powers and Abilities
Now being mystically blind, his eyes glow a strange color. In his blind state, the cane is disguised and he is essentially powerless, except that he can see the magical creatures and forces that are hidden from normal site, for his true eyes are in the magic realm. When he activates the cane, which is made of acacia wood, he can summon new protoplasmic eyes to see the "normal" world that we see.
Notes
Dr. Acacia is an open source character created specifically for use by anyone. Feel free to use it any way you wish; author citations are not necessary.