SELECT
    CASE
        WHEN g.Grade > 7 THEN s.Name
        ELSE NULL
    END AS Name,
    g.Grade,
    s.Marks
FROM Students s
    JOIN Grades g 
    ON s.Marks between g.Min_Mark and g.Max_Mark
ORDER BY 
    g.Grade DESC,
    CASE
        WHEN g.Grade > 7 THEN s.Name
        ELSE NULL
    END ASC,
    CASE
        WHEN g.Grade < 8 THEN g.Grade
        ELSE NULL
    END DESC,
    CASE
        WHEN g.Grade < 8 THEN s.Marks
        ELSE NULL
    END ASC;