These items are level 25 plus 3 per level.
Valkyries can have other abilities as the result of the magic spears and armor they receive when they are created. Valkyries have a glow about them so it's easy to pick them out. You can only have one Valkyrie at a time.
A Valkyrie is much more powerful than a Hireling and you can create one whenever you have enough mana.