Silent Hill

Silent Hill 4

Spoiler note: this page contains information that may reduce frustration when playing SH4, and I've tried to make it completely spoiler-free.

Eileen cannot die by damage, however your ranking will be affected by the damage she takes
If she has a weapon equipped, she will help fighting, if not, she will keep in the background

If the haunting is a problem, use a Holy Candle at the center of the haunting
De-equip Saint Medallion in Room 302, use Holy Candles instead (Saint Medallions are worth much more in the field)

Cannot be killed
Can be pinned using a Sword of Obedience - pummel the Victim into submission (e.g. with your trusty Axe) and use the Sword as he hits the ground - you must be fast, he's up again in no time
Use Sword of Obedience on "boss" Victim, and retrieve the Sword again when you are nearly done with the level. That way you don't have to worry about that Victim throughout the level, and you will never lose your Sword.
Richard Braintree haunts 'Building World 2nd time' and even though he walks on the ground, he is a normal Victim and can be pinned. It's pretty hard, though, and you might want to use a Silver Bullet on him.