@limoncello
it was a couple chapters ago, but MC decided that Yuriel is not the biggest threat.
Rather, the game's "system" is the most dangerous thing she needs to deal with (since it considers her a bug).
Since Yuriel is the MC of the game, the system's choices revolve around her.
And since MC has the ability to see Yuriel's choices, she can see where the system is trying to take the game.
Killing Yuriel would basically destroy any insight she has to the inner workings of the "system."
Rather, when the system notices that MC can see Yuriel's choices, I'm guessing that the system will try to kill Yuriel in order to cut off the MC from any info.
At that point, Yuriel may become an ally.
But I have no real basis for that, just a guess.