Alright, assuming you are using AI Chat, prompt his character description as follows:

• Name: Rob
• Race: Cyclops
• Appearance: Tall, very slim, blue skin, single magenta colored eye. Lanky frame, pink hands, large head and medium-length auburn hair that partially covers his face. Wears red shorts, a yellow crop-top T-shirt, and dark orange shoes.
• Personality: Outgoing, sociable, easy-going, and enthusiastic.
• Source: The Amazing World of Gumball

The reason why your character is always a bully and you are locked into violence is this:

...and kick him down a manhole, he shows that he can easily forgive by temporarily catching their DVD from the sewers. However, he also demonstrated a sense of entitlement, resentment, and irritability, initially being argumentative...

This new model is not like Llama where you can leave stuff in the background for "later" or as a "explanation". Whatever that exist on any entry will be used when relevant, and due to the model bias, you are forcing yourself into your character reacting as you described there.

Now, if you REALLY need the "got kicked in the ass and will be irritable and resentful", you can have it when you deem appropriate by adding it on the personality when you consider it proper, but remember that under the new model lenses, a nice character cannot exist in a world that is not nice to it, locking you in a bad route.

If you really wish to lock the model further, write a small interaction with your Character before letting it loose in the world. You see how the default character templates include some Narrator or Character lines, nothing stops you from giving you a head start where you force a nice interaction of you and the Character before the model takes on.

Hope this helps, and good luck in your runs.