Wraiths are slightly different in this game than in previous ones. For starters, they can summon purple phantoms of itself to attack, although these phantoms are pretty weak. They can also throw their blades at you like boomerangs and burrow underground, where a grapple can pull them back to the surface. Another move they can do is burrow underground, then move quickly in a straight line, creating a dark fire that hurts when it touches Kratos.
One of the most important parts when fighting these is to always make sure they're above ground. Also, make sure they don't get a chance to summon the phantoms. They can be launched with the Hold Triangle move, so use that to do damage. If you see a red halo, grapple the Wraith to do a brutal kill.
