Deathseek (3.5e Sacrifice)
From D&D Wiki
To enter the Gate is to die. Be it living or undead, all things 'live' through the Gate. Return them to the Gate, and they return to base neutrality, to oblivion. With this sacrifice you may duplicate the effects of either Circle of Death or Undeath to Death. You may affect up to 9 HD, or up to half your caster level, whichever is greater. Unique in its casting, they require a focus each. Circle of Death requires a black pearl mounted in jewelry worth 10,000 gold as its focus, while Undeath to Death requires a 10,000 gold diamond mounted in jewelry.
Health Cost: -11 (and the appropriate focus).