One common theme is redemption. Often, Cifer is depicted as a character who has made mistakes in the past and is seeking to make amends. Another theme is power struggle. Since Naruto is a world full of different levels of power, Cifer is sometimes caught in the middle of power battles between clans or villages.
In this fanfiction, the plot could start with a strange magical phenomenon that causes Harry Potter to be reborn as Ulquiorra Cifer. He initially struggles with his new form and the cold, emotionless nature that comes with being Ulquiorra. However, as he gets used to it, he starts to use his wizarding skills in the Bleach world. He could use spells to enhance his combat abilities as Ulquiorra. The story might then lead to a great battle where he has to face a powerful enemy that is threatening both the magical and spiritual worlds. Along the way, he might also meet some characters from the Harry Potter series who have also been transported into the Bleach world in different forms, and they have to work together to save both universes.
One great Naruto Cifer fanfiction is 'The Cifer's Redemption'. It explores Cifer's character in a unique way, showing his growth and how he overcomes his inner demons within the Naruto universe. Another is 'Cifer's New Path' which focuses on Cifer's journey to find his true place among the ninja clans.
There may be such a fanfiction out there. Fanfiction writers often come up with the most creative crossovers. If it exists, it might explore how Harry Potter's character would interact with Ulquiorra Cifer. Maybe Harry, with his courage and magical abilities, would face off against Ulquiorra's unique powers from the Bleach series. It could also be a story about how the two very different worlds they come from would collide and change each other.
Well, typically, a successful cartoon drawing of a rabbit hole would include elements like a well-defined entrance, perhaps with some roots or grass around it. The inside could show different levels or chambers, with the rabbit looking curious or cautious. Also, the use of colors like earth tones and soft lighting can add to the charm.
Perhaps the cartoon man is picking up the dog poop to avoid people stepping on it and getting dirty. Or he might be trying to set a good example for others to follow and keep public places tidy.