```python
from fastapi import APIRouter, HTTPException
from typing import List
from models.book import Book

router = APIRouter()
books = []  # In-memory storage

@router.post("/aiderman", status_code=201)
async def save_books(book_list: List[Book]):
    """Save a list of books to the database"""
    if request.method != "POST":
        raise HTTPException(status_code=405, detail="Method Not Allowed")

    books.extend(book_list)

    return {
        "method": "POST",
        "_verb": "post",
        "message": "Books saved successfully",
        "books_saved": len(book_list)
    }
```

This endpoint accepts a list of `Book` objects in the request body and saves them to an in-memory list called `books`. It returns a JSON response with the number of books saved and the required method metadata.

Ensure that the `Book` model is defined in `models/book.py` with the necessary fields, and imported correctly in this file.