The good thing is that Liorah already has a lot of the background information necessary, so the conversation doesn’t need to be a monologue. It can be a really quick explanation.
One way I see explaining this is a brief conversation, either with Hakan himself, or simply someone on his side, such as a captured soldier or the messenger that has come to ask for their surrender since their king is gone, etc. It could go something like this:
Liorah: How could you do this/this is an outrage/we’ve never done anything to justify this betrayal.
Scene antagonist: Don’t pretend innocence/How dare you say that/You killed OUR QUEEN as she was HELPING THE WOUNDED—you are not the wronged party here. I/the king is simply preventing the situation from ever happening again.
The scene could then end, they could change subjects, they could argue over whether that is true or not, or something else entirely could happen. Liorah doesn’t even have to believe him, but I think something along the lines of this short exchange could explain everything the reader needs to know about the king’s motivations.
The cake is a lie. acaylor.com