However, writer Peter David was uncomfortable with this, and ultimately editor Bob Harras independently came to the conclusion that Legion should not be used in the series.

David explained "I don't mind building a story around [Legion], but working him into a group – you're really asking for a bit much from the reader.

Believing that a group of people will come together to form a team is enough of a suspension of disbelief... 'Oh, by the way, one of them is so nuts he shouldn't be setting foot off Muir Island'... that's asking the reader to bend so far he will break.

Some of the alters resisted Karami, most notably Jack Wayne, a swaggering adventurer who was telekinetic, and Cyndi, a temperamental, rebellious girl who was pyrokinetic.

[7] During his time at Muir Island, David saved Moira and Wolfsbane from a fatal accident by accessing the telekinetic abilities of his Jack Wayne alter.

Destiny gave David vague prophetic guidance about the great world that could exist "if only, years ago, Professor X had been given a real chance to fulfill his dream.

"[11] David understood these words as a directive to travel back in time and kill Magneto, Xavier's greatest adversary, to allow Professor X to achieve the dream of human-mutant coexistence.

[12] Ultimately, Bishop repairs the timeline by enlisting the aid of the new reality's X-Men to travel back in time to the moment of Xavier's murder.

There, Bishop confronted Legion, using David's own power to create a psionic loop that showed him the damage that his actions would cause.

Unbeknownst to Doctor Nemesis and Professor Xavier, however, David's mind subconsciously perceived this intervention as a threat and created a "psychic antibody," a powerful new personality, to defend itself.

Within this pocket reality the 'Moira' personality was practically omnipotent, creating and controlling random soldiers for Legion and the other mutants to kill.

[23] With the Age of X incident underscoring the potentially apocalyptic scope of David's power, Professor X proposed a new approach to help Legion retain control of himself.

To this end, Doctor Nemesis, Madison Jeffries, and Reed Richards designed a Neural Switchboard Wristband for David that allows him to access the powers of his alternate selves without being controlled by them.

[24] While tracking down and re-absorbing the alters, David accidentally absorbs Rogue and suffers severe nervous damage after releasing her time.

[25] To aid his recovery, Professor X left Legion with Merzah the Mystic, a powerful empath and telepath who ran a Himalayan monastery.

In the final issue of X-Men: Legacy, Legion, reaching the full extent of his powers, decided to erase himself from existence.

In a desperate attempt to save himself, David sought out the help of renowned young psychotherapist Hannah Jones to delve into his fractured mind and fight back this dark alter[29] While Jones was ultimately able to help Legion defeat Trauma, she remained trapped in David's psyche (her body in a vegetative coma).

[30] As the X-Men race around the globe to fight the temporal anomalies that have been springing up and to corral the hundreds of Madrox duplicates wreaking havoc, Legion arrives at the X-Mansion, seemingly in control of his powers and psyche.

While the young X-Men try to ascertain what he wants, elsewhere Jean Grey and Psylocke team up to psychically purge whatever force is controlling the army of Madrox duplicates.

However, with his control broken, Legion goes berserk in the mansion, attacking the young X-Men and ranting about a vision of the future.

Legion has over a thousand different personalities (the exact number is unknown), and his mind can create additional alters in response to external or internal events.

[34] Since the abilities of his personalities stem from his subconscious alteration of reality, Legion is theoretically capable of manifesting any power he can imagine.

Following the Age of X, David briefly used a Neural Switchboard Wristband engineered by Doctor Nemesis, Madison Jeffries, and Reed Richards.

To overcome Professor X on the psychic plane, this personality took on the face of Moira MacTaggart and claimed that it would make a world where Legion could be happy.

When finally confronted about its actions, the personality made the Force walls fall, allowing the human armies to attack.

'Moira' announced her intention to destroy the 616 universe as well as the Age of X and to create a new safe place for David to live happily forever.