Adamant Sentinel

When the adamant sentinel is at 0 HP, it isn't destroyed. Instead, it enters repair mode, during which it's Slowed 1, can't take reactions, and can take only the Self-Repair action. Once it has more than 30 HP, it can use any type of action and can use reactions, though it remains slowed 1 and can't take any reactions until the start of its next turn. If a critical hit with a Vorpal adamantine weapon reduces the sentinel to 0 HP, or if such a weapon hits it while it's already at 0 HP, the sentinel is destroyed.

On a critical hit, the adamant sentinel's fist Strike breaks the target's armor, if any, in addition to dealing damage to the target. If the target has a shield raised, the sentinel breaks the shield instead.

The adamant sentinel Strides up to its Speed, pushing back each creature whose space it moves into and damaging them if they try to stop its movement. A creature can try to bar the way by attempting a DC 45 fortitude save. Critical Success The sentinel halts its movement and cannot enter the creature's square. Success As critical success, but the resisting creature takes (3d10+17) bludgeoning damage. Failure The resisting creature takes (3d10+17) bludgeoning damage, and its armor, if any, is broken. If the resisting creature has a shield raised, the sentinel breaks the shield instead.

The sentinel repairs itself, regaining 30 healing Hit Points.

The sentinel vents a 30-foot cone of superheated steam from its internal forge. This deals 15d6 fire damage to all creatures in the cone (DC 40 reflex). The sentinel can't use Vent again for 1d6 rounds.