Mathilde theoretically can get help with developing individual aspects of Branarhune it when that individual aspect can incorporate already-existing elements from elsewhere, but in that case it's something that she'll do automatically and there's no need for the thread to try to micromanage. What she can't get is someone to work alongside her in developing the entire style, because the base of it is half Greatsword and half Gazul Templar and she is literally the only person in the world who has that combination of styles, because it depends on a combination of runes that literally no other sword but hers has, and because you can't safely spar with Branulhune without deactivating the Runes Mathilde's style is trying to take advantage of.