I like to use an axe for wayward roots.
My preference would be rototill vs add soil, simply because looks like there's a hump there already. Don't need to slice seed if you have loose soil to begin with.
I used to work on a crew installing landscape at new apartment complexes an retirement homes. All the trades would leave massive messes and guess who gets to clean it up? The last guy there, the landscaper. Lots of trash. No topsoil to use. Then once we completed our work the trades would walk through it trampling mulch and plants and leaving muddy holes in the sod.