I think the 'trust' she has in the ML's words is because of how she perceives the ML to be based on the novel(?) she read. She thinks he's a soft hearted and kind person who wouldn't dare to hurt anyone if he had the choice, because that is the narrative the novel gave to her. She keeps mentioning how hard all this shady work must be for the ML or how hurt he must be to have to kill his own due to family traditions or wtv . Because of what she has read in the novel and how the ML acts around her, he's nothing but a harmless puppy to her. Only we know that he's actually a wolf in sheep's clothes
You right, she too trusting cuz she says herself that she only read halfway but she is so sure he's some saint Jajaja, she gonna be surprised later
My point with all of this is that she believed him too fast...with literally no guarantee whatsoever that he will fulfill his part of the deal. Before she proved she was helping him ok cuz he had all the power to kill her right there cuz they literally meet right that second but after all she did she still has no guarantee but his flimsy words of promise and she is totally fine with it.
Seems pretty stupid for her to behave that way all happy and chill about it despite only having his word to believe. At the very least it would have seem less dumb if she was worrying over the issue or trying to make him sign a promise with magic.
Again it's good but that behavior is just not it. And please the fighting or battle scenes look kinda awkwardly done or rushed so they dont flow correctly loking a bit unnatural, so you cant really gwt hyped up at the battles...they are wasting potential because all those elemental powers are perfect for super fight scenes and we getting this mid scenes even with those two complains of mine, the series is good, so I hope they improve the power scenes so people can enjoy reading even more
For example in I Became the Wife of the Male Lead where they used elemental magic, the fight or power panel were captivating and is the cherry on the cake for a good plot and characters