Undead Brass Knight

A Brass Knight that died and was resurrected by the Necromancer. However, their will of steel prevented them from being controlled by the necromancer. When slain, they will resurrect after a few seconds. There is a rare chance to find this variation instead of the normal knight in a Gilded Catacombs.

Abilities
For every 10 Health he lost, he gains 0.5% chance increase on all above skills.
 * Parry: When attacked with a sword, has a 30% chance to negate the attack.
 * Arrow Deflect: When fired at with bow and arrows, has a 30% chance to deflect the arrows.
 * Disarm: While crossing swords with you, has a 10% chance to make you drop your sword.
 * Critical Strike: While attacking, he has a 10% chance to strike you critically, dealing double damage.
 * Crazed Dead: Basic attack deals 1% of missing health as bonus damage.
 * Undying Will: Upon receiving a fatal blow, his health will be set to 1 and are immune to any damage as he collapses into a pile of armor and bones. After a few seconds, all pieces of him will begin to reassemble themselves, resetting his health back to 400.

Strategy
Why are you even reading this section when this boss is unkillable? Fine. The combat is pretty similar to the normal version of Brass Knight, only much more harder as all of his skills have been upgraded. You need a certain item in order to put him to rest.