This concept is based off of an scp foundation wiki monster. http://www.scp-wiki.net/scp-231
An ancient deity called the scarlet king exists across several dimensions, but is prevented from entering our world due to a magical barrier. A cult formed in his name with the purpose of bringing him into the mortal realm to rule humanity. To accomplish this, they opened up a portal between dimensions, allowing his essence to seep through and take residence within an infertile cultist as a developing fetus. However, the gods essence is so massive that it cannot be contained within one individual, and must disperse his essence among other individuals in order to cross over. Thus, seven volunteer cultists were chosen to carry a "shard" of the deity, becoming what the cult referred to as the seven brides of the Scarlett king.
These seven were captured and taken in by secret governmental forces, who seek to prevent these shards from being born. This is accomplished through a process called Montauk-110, an expensive and complex sealing ritual involving incantations, ritual circles, and the sacrifice of a D-class prisoner. This ritual must be performed every 24 hours when the brides go into labor. If the ritual is successfully performed, it causes the beast to subside and prevents the birth. If unsuccessful, the seal is broken, allowing the deity to cross over and begin it's period of darkness.
Only the 7th bride remains, the others dying due to suicide or complications during labor. The deity could easily be eliminated as a threat by killing the final bride. I need a way to make the sealing ritual continue to be necessary to prevent the government from taking that step. How can I make this setup possible?