Blood Clock

This spell cannot be countered.
Flash Hexproof
{r}{b}{t} Sacrifice this artifact, all players shuffle their hands, graveyard, and permanents they control into their libraries. Each player gains
up to or loses down to 40 life. Search your library for a card put into it this way that is not named Blood Clock. You may put that card onto the battlefield tapped. Each opponent creates a 1/1 black and red clockmaker creature token.

An ancient tool used as a last resort.