I want to write a fanfiction with a Slytherin Harry, but let it be realistic, no mini politicians at school, without all pureblood students knowing about occlumency, occlumency is a more "dark" art, not so well known and practiced, so it's not normal let all little idiots know that!

No noble houses and gringotts, no gentle goblins. (even an idea of mine is to write about a Goblin rebellion, oh and the goblins are not the good guys in this story)

I want to write a powerful but realistic Harry, no magic by intent, no mastery of occlumency in two months, (Harry won't even know about occlumency until at least the fourth year, and as he's going to be self-taught, it's going to take a while to learn and master)

Ron and Hermione are not going to be the main characters here, without Harry to be there to "remediate" the situation, the two are not going to be friends, Ron is going to be basically as relevant as Seamus. Hermione is going to be an annoying girl, but over time, she will realize that she herself is the cause of not having friends and will start to be less annoying, BUT WILL NOT BE FRIENDS WITH HARRY. No bashing, I hate bashing.

Friendship ideas, Neville! Yes, the shy and awkward boy is going to be Harry's best friend here! But why? Simple! You see, they're both shy and bullied, so over time, they'll both have a strong friendship, which during the first year will grow stronger.

Draco will be another friend of Harry's, but not at first, Draco will mostly ignore Harry, but our Draco has no filter, so he'll end up saying some shit and pissing Harry off, so that's our catalytic event that will slowly make both of them the boys come closer. No slash.

Now, about Dumbledore.... Dumbledore will be almost the same as canon, almost... He will be more active in Harry's life, mainly he will be worried about Harry's safety in Slytherin, he will make some decisions that could drive Harry away him, but nothing for "the greater good" or any of that goosebumps. Just a kind old man who is rash and thinks he's carrying the world on his back.

Harry is going to be powerful, he's going to start out as an ordinary kid, but by his fourth year, he's definitely going to be one of the most powerful in the school, obviously not so powerful as to take on ten seniors and walk away without a scratch. .. But let's just say he's going to be well above average, and the teachers' attention will be riveted on him.

 

Be aware of the tropes and don't put them into your story.

 

OK. Then write it. What's stopping you?