Conversation so far:
Does Legion have a secret identity?
CANNOTANSWER.
What superpowers does Legion have?
psionic power.
What kind of psionic powers?
Jack Wayne, a swaggering adventurer, who commands David's telekinetic power.
Why does Jack Wayne control his power?
The trauma caused David's personality to splinter, with each of the personalities controlling a different aspect of his psionic power.
What was the trauma that caused this?
David was among the victims of a terrorist attack, in which he was the only survivor.
Where did the attack happen?
CANNOTANSWER.

Question: Who else controls his powers?
Self-contained rewrite: Besides Jack Wayne, who else controls Marvel character Legion's powers?