While Neil would probably fully protect him because he was so obedient to the orders that the imperial orders reached all of his descendants.
But Neil Rudwig also wouldn't have possibly sacrificed his life for Cattarina. The woman he doubted the most could side with the Majesty Crown Prince and become the Crown Princess.
Monna could only let out a long sigh when she realized that only her family was the most loyal and sincere to sacrifice anything. So that on this second life and opportunity, Monna promised herself and her family.
That he will always protect them no matter what. Will not let them get hurt or be put to death.
Neil's confused gaze had already dispelled Monna's farther and farther back. She knew that he had caught her daydreaming and thinking nonsense.