Neena existed when the world was filled with spiritual energy and was a dark place. Good or Evil didn't exist. Just The All (spiritual energy that is part of the Earth and air). Thousands of years ago Neena and her mate discovered the Nexus. At first they were afraid of what they found however they later pushed aside the fear and tapped into its power. Neena tapped into The All's power and absorbed more of The All than any mortal was supposed to have. She shared this power with her mate and it granted them immortality and invulnerability. It bonded with them for all time, it created a state of being that is beyond the physical universe. A place of pure happiness and bliss, they shared this with The All. Soon their presence in this higher plane began to destroy the Earth. To allow The All to once again flow freely through the Earth Neena and her mate had to give up their powers. Once given up they were forced from the higher plane. While back on Earth Neena gave birth to twins. The first child was female (the first born natural witch) she had the same powers as her mother albeit on a weaker level. The second child was male, he was born with the same powers but abused them giving birth to race of Warlocks. It is later revealed that the Warren line
is directly descendent from Neena. Every witch that has been born has had a finite piece of The All inside of them which was the spark to access their powers. With every new witch born The All was becoming drained. Neena's mate returned to the higher plane however it was not by his own free will. One day he just vanished. His returned was determined by the Grand Design.
Neena aka Isabel
In "To The Warren Born" (a 6 page story in the Charmed comic) she appeared as a cryptic woman who only spoke in whispers and was said to have the power to see the future. There she met Charlotte Warren
(the beginning of the Warren line of witches) she gave Charlotte a talisman which would later be named the Triquetra. She told Charlotte to go to a woman who would help her give birth to her child ( Melinda Warren
). However Charlotte revealed that she had conceived the child before marriage and her soon to be husband was missing, she wanted to wait until his return. The triquetra guided to Charlotte to Eva (the village care giver) who would help her give birth to Melinda which would start the the Halliwell line.
Neena aka Isabel aka Victoria
Hundreds of years later Neena appeared in San Francisco under the guise of Victoria. There she and a Warlock named Hogan waited in a club for a demon named Weasel. However an Angel of Destiny appeared and warned Neena that her
plan was not apart of the Grand Design and she would be stooped. However Neena sent the Angel of Destiny to a strange and unknown plane of existence. After she banished the Angel Weasel appeared and handed her a map to a cave by the Golden Gate bridge. Neena soon kills Weasel because he tried to flirt with her. While in the cave Neena and Hogan are lair filled with lava. Sometime later Neena and Hogan talk with a smoke being who appears to be their leader. Later Neena and Logan kill Brent, a witch that was Paige
's charge. Soon after the two go to the site of The Hollow and destroy the two new guardians and take soil samples which they use to summon a golem which houses the Source of all Evil.
After summoning the Source Neena leaves Hogan behind saying she has things that are more important to her to work on. The "work" is later revealed to be a spell that could share the incredible powers of the Source.
Neena is seen in the underworld yelling at the Vampire queen. The "fight" escalated with Neena easily using her powers to use stakes to kill the Queen. In the underworld Neena gathers a group of demons to attack the Elders. Soon a massive battle takes place on the Golden Gate Bridge. The Elders
are out numbered but the Charm Ones soon arrive to even the odds. She faces them and defeats them by sending Piper to
the void where she sent the Angel of Destiny, forcing Paige and Phoebe to orb away. As they were no match for her without the power of three.
Neena has the powers of the average witch such as spell casting and making potions but to an extremely
advance level. She can also generate powerful beams of magical energy, create portals, control the earth, banish extremely powerful beings which have been shown to be immune to witch's powers,and can throw fire from her hands. Her powers are so strong that she can effect the underworld as a whole, which is a testament to her strength since it has been said and shown being in the underworld weakens a witches powers. Since she has absorbed the powers of the Elders as well as The Source Neena is easily the most powerful being in the Charmed universe. It should also be noted that Neena is extremely intelligent(wrote a spell to share the Sources' powers) and an expert strategist and manipulator (tricked him into working for her).