Black fog

From Yu-Gi-Oh!

The black fog was a a cloud of dark matter the Dark Signers spread through Satellite. Anyone who got engulfed by the fog, had their body absorbed into it.

When Roman Goodwin Summoned Earthbound Immortal Uru, the fog was sucked in the Earthbound Immortal giant heart. As the people that were trapped by it were automatically sacrificed to Summon Uru.

Thus this also ocurred again with Carly Carmine, who summoned her Earthbound Immortal, Aslla Piscu through the same method.