Language / All-nighters / traction session / legions / levels - Synonyms needed [4]

hey, I need to find synonyms for the following idioms and words. I know their meaning but I need some other words which can be used as substitutes.

An all-nighter- ?
A traction session- ?
To be legions-?
To pull the levers-?

and if u need some context, these words are taken from the following sentences:

While recuperating in the hospital and later during grueling traction sessions, she eased her pain by turning her mind to a dream she'd long harbored: buying an airplane and flying it to Europe.

. They worked around the clock for weeks, pulling multiple all-nighters to get the job done.

LOOKING AHEAD to her new role at the CIA, Haines's supporters-and there are legions-say not to underestimate her.

And she had begun to notice that the activists who knew best how to pull the levers of reform were lawyers. So she gave up the bookstore and applied to law school.