Rayla knew that she promised to kill Callum, and she knew that they had to save Xadia. But at what price? She is forced to point an arrow at her lover, but cannot will herself to kill him. Unfortunately. Callum does that on his own.

"You have to choose Rayla". When Rayla is forced to choose Callum or the good of humanity, it doesn't come at an easy price. Too bad that someone will have to make that choice for her.