After defeating Debilitas with the chandelier, doing so will incapacitate him. When he comes to, he sees Fiona silhouetted through the church window, making her look like an angel. Once on his feet, Debilitas bows respectfully to Fiona and leaves the room.
Ending A. Debilitas simply bows to Fiona and allows her to leave the castle.
And after that, he goes to work pruning a bush, humming a tune to himself. He seems to be content doing that even when there is no one left to order him around, and those people are also the only ones he needed to fear abuse from.
Fiona and Hewie's relationship is a heart-warmer in general.
After Fiona saves Hewie for the first time, he later comes back to save her from Debilitas.
When playing on Hard mode, Hewie's comments are jotted down instead of Fiona's. One of them mentions how Hewie loves (what he considers) playing games with Fiona.
Hewie keeping Daniella from attacking Fiona before Daniella's boss battle.
When she finds Hewie shot (which was obviously the work of Riccardo), Fiona bandages him up and lets herself get chased by Riccardo so that he won't kill Hewie while the poor dog is defenseless.
Hewie saving Fiona once again when she is locked in the Water Tower. If you are playing on Hard mode and look at Hewie's most recent comment, it mentions that he was looking all over for Fiona.
After defeating Riccardo on Hard mode, Hewie says in his latest comment that he and Fiona are soulmates.
In Endings A, B and C, Fiona appears to be nervous as she tries to put the key into the castle's main gate. However, she calms down when she hears Hewie beside her. Fiona thanks him with a smile and unlocks the door, leaving the castle with her faithful companion.
If the player finds the ball in the garden, they can use it to play fetch with Hewie. It doesn't serve any other purpose.
"Precious Hewie." A gentle music box melody that plays whenever Hewie and Fiona share a tender moment together. Made all the more heartwarming if you're a dog owner yourself.