Hel-Shadows are projectile-wielding undead. Their icy missiles can inflict freeze, limiting Kratos' movement for a time.
Hel-Shadows can be an annoyance when they're teamed up with other undead warriors. They'll sit in the background as long as they're allowed and pelt you with projectiles at a surprisingly fast rate. Needless to say, you should try and deal with them first — especially before they start inflicting freeze.
Their missiles can be blocked, though — and parried if you get the timing down. Get through their attempts, and they're easy enough to kill, with low health and a low stun threshold.
How many Hel-Shadows have you smashed into submission? Be sure to check out our full God of War Ragnarok guide for information on how to beat every enemy, and much more.