Blackened Splinter

A charred shard the dead can neither ignore nor escape.

A crude, magical, fireproof sliver of blackened wood. Undead who see it are drawn to it or thrown into deep agitation.

When you touch it to an undead entity, roll 4d6. If the total exceeds the entity's current HP, it passes through the Last Door for good; otherwise it is transfixed briefly. Either way, the splinter vanishes.