The mask keeper/Visages tried to keep fighting until the end and Scielle was only able to overcome because she didn't hide her trauma or her feelings
Why did Sirene then incapacitate everyone except Lune, and even gave her the opportunity and ideal location to kill her and harvest her heart?
I originally thought it was because being created by Renoir they would have wanted to die so it could go to someone on his side but the behavior of Visage to keep trying to kill them goes against that.
Just felt weird to me.