Phase 1: Humanoid Form
Cornell is a fast and aggressive opponent. In his humanoid form, he uses quick claw attacks and a powerful charge. His attacks are often preceded by a growl or a brief wind-up animation. Focus on parrying his attacks to create openings. A successful parry will stun him, allowing you to unleash a short combo. He also has a ranged ground pound attack that sends shockwaves; jump over these or dodge to the side. Avoid getting cornered, as he can quickly overwhelm you. Use Light Magic to heal if you take too much damage, and Shadow Magic for burst damage after a successful parry. Daggers can be used to interrupt his charge attack if timed correctly.
Phase 2: Werewolf Form
After taking significant damage, Cornell will transform into a massive Werewolf. In this form, he gains increased health, damage, and new attacks. He'll perform devastating leaps, powerful claw swipes, and a dangerous spinning attack. The key here is patience and evasion. Dodge his leaps and swipes, and wait for him to finish his attack animations. After a large attack, he'll often be vulnerable for a brief moment. Use this window to land a few heavy attacks. He also has a roar attack that can stun you; try to dodge away when you see him preparing it. When his health is low, he'll become more desperate, attacking more frequently. Keep your distance, use your sub-weapons (Holy Water is effective), and only attack when you have a clear opening. Eventually, a QTE prompt will appear, allowing you to finish him off.