From Pathfinder #149: Against the Scarlet Triad, which isn't enabled.

Nethysian Bulwark

ITEM 16

UNCOMMON MAGICAL

Price 8000 gp

Bulk 1

AC Bonus +2

Hardness 10

HP 40

BT 20

This round shield is often fashioned to resemble the religious symbol of its dual-natured namesake. A Nethysian bulwark is a high-grade cold iron shield (Hardness 10, HP 40, BT 20) that defends the wielder and can explode with retributive force when struck.

Activate envision

Trigger The shield becomes broken when performing a Shield Block

Effect The shield explodes in a burst of bright light and shadowy tendrils, releasing a 15-foot cone of force that must include the attacker if possible. The cone deals 6d8 force damage to all creatures in the area (DC 34 basic Reflex).

Pathfinder #149: Against the Scarlet TriadOGL