My Friend Said Levi Was Erwin’s Slave, She Said This Is Basically Confirmed, What Is Going On ???

my friend said levi was erwin’s slave, she said this is basically confirmed, what is going on ???

Your friend is talking shit Anon.  I’m guessing that they’ve conflated Eren telling Mikasa that she is a slave to her Ackerman instincts in chapter 112 and Kenny telling Levi that everyone is a slave to something in chapter 69.  However, Eren is painting the Ackerbond in the bleakest possible light and the jury is out as to how much truth there is in what he tells Mikasa.  Also Kenny’s final words to Levi are often misinterpreted.  When he asks Levi what he is a slave to, the answer is not Erwin, the answer is “being a hero”.  In other words Levi is a slave to his strength, to being Humanity’s Strongest, to being a hero that fights for humanity.  

Isayama explained this in the Answers book: 

Isayama: In American comics, portrayal of struggles are tied to the idea, “With great power comes great responsibility” - this is how it applies to Levi as well. If he possessed no power, he is just another man without responsibility. But the fact that he has great amounts of power means that he carries an immense amount of responsibility. When Kenny said, “Everyone is enslaved by something,” and questioned Levi “Whose slave are you?” Levi also recognized that he is tethered to his own strength, as well as the duty of “I must become a hero”

[Translation by @fuku-shuu]

And just to hammer the point home, Yams also said that he was at pains to portray Erwin and Levi’s relationship as being mutual and equal. 

So yeah, anyone who claims that it’s been confirmed that Levi is Erwin’s slave is basically talking shit.