The Protector's ward is a somewhat powerful shield that can only be obtained as an uncommon drop from a spiritual guardian in Daemonheim. The shield requires 65 Defence to wear, and thus its defensive bonuses fall directly in between those of the argonite and katagon kiteshield.
If examined closely, it looks very similar to the guardian's ward, except with a less elaborate design. The shield also boasts a different colour scheme than the Guardian's shield, and the eye in the centre apparently "sewn shut".
The ward's usefulness has decreased since the Evolution of Combat update, as it, along with the guardian ward, no longer provides the magic defence bonuses that set it apart from the standard metal kiteshields.
Marmaros, the Rewards trader outside Daemonheim, appears to be cowering behind one of these. It is unknown if it carries the "taint" of Daemonheim.
Both the protector's and the guardian's ward are considered magic shields. However, there used to be no wands in Daemonheim and all staves are two-handed. Therefore those two shields could only be utilised while casting spells using a blastbox/surgebox, wands or runes from the backpack.
Prior to the Evolution of Combat update, the protector's ward specialised in magic defence, being overall comparable to the argonite kiteshield. Since then the ward has what could be seen as either a minor improvement or degradation, as the defence and life point bonuses may not have been increased enough to compensate for the loss of its reasonably unique magic defence bonus.