1) Bitterly 2) Brutally 3) Cruelly 4) Fiercely 5) Nastily 6) Savagely 7) Spitefully 8) Unkindly 1) Brutally 2) In a vicious manner 3) Savagely 
[adv] - in a vicious manner
viciously 1. A description of people or actions that show an intention or desire to hurt someone or something very badly. 2. A depiction of an object, condition, or remark that causes great physical or emotional pain. 3. Corruptly; in a manner contrary to what is considered right and a corruption of moral principles, propriety or purity.
brutally adverb in a vicious manner; `he was viciously attacked`