Steel Princess (Royal Elite #2) by Rina Kent

The princess isn’t supposed to dethrone the king.

Elsa
He said he’ll destroy me, and he did.
I might have lost the battle, but the war is far from over.
They say it starts with one move to dethrone the king.
No one mentioned he’ll yank me with him on the way down.

Aiden
If Steel’s little princess wants a war, then war it is.
There’s only one rule: my rules or none at all.
By all means, show me what you got, sweetheart.