Rethilgore, having already been killed in the past, has a chance to be summoned as a ghost worgen by Baron Silverlaine when his health is brought to ~25%. He does not drop any loot nor does he say anything during the fight.
Rethilgore was the first mini-boss that players encountered in Shadowfang Keep. He guarded the cells of both Deathstalker Adamant and Sorcerer Ashcrombe which players needed to progress further into the keep.
[Soul Drain]ωϖ—Immobilizes an enemy for 10 sec. and drains 35 health, transferring it to the caster.
Strategy
Rethilgore was not very hard to kill. He did 54-62 physical damage in melee, mitigated by armor. He would cast Soul Drain, which immobilized a player for 10 seconds and drained 35 health, healing himself with it. The easiest way to beat him was to just bring him down with attacks and spells. Players had to look out for worgs and wolves around him. They were weak, so could be killed quickly.