Mysterious Cubes

These are boxy artifacts scattered across the planet whose purpose is to bridge contact with the being called God. Sitch labels them out-of-place artifacts, and Blast describes each one as a kind of transmitter that warps the surrounding space so a person can reach God, who dwells in a separate dimension outside the ordinary universe. Simply making contact with a cube causes God's voice to sound inside the toucher's head.

A cube turns up as far back as eighteen years ago in Tatsumaki's memories, held by Blast the night he rescued her from a hybrid monster. A second is later unearthed by Saitama, Manako, and Flashy Flash in the collapsed remains of the Monster Association Headquarters. Blast admits he has been gathering the many cubes strewn about the world, framing it as a hobby, though his real aim is to keep others from claiming the gifts God hands out.

The cubes are staggeringly heavy: one pins Flash's arm in place, another sinks into solid stone after Saitama drops it, and Manako cannot budge it at all. Beyond their weight, they bend space and time nearby, generating a pocket where time crawls slower than the world outside, which is why Blast urges the group to leave quickly when they linger near one underground. He explains that a cube can drop someone into a gap in time, and its interference twists teleportation as well; after Blast whisks Saitama, Flash, and Manako to the surface, they do not arrive at once but emerge much later, an instant to them while a long stretch passes elsewhere. A cube can also remake a human into a Mysterious Being: by laying hands on it and voicing a wish, a person may be granted power, but anyone deemed unfit faces forfeiture and dies, and the standard God uses to judge worth is never made clear.

The cubes are tied above all to God, with Blast and Empty Void also linked to them. Blast is their chief pursuer, having warred against God for two decades while collecting and studying the objects with a group of collaborators; Sitch reveals that Blast even faced God directly two years earlier during a fight with Elder Centipede, refused the offered bargain, and survived. Empty Void once kept a cube sealed in a glass tank within a restricted zone of the Ninja Village, where an instructor intended to use it to test whether graduating young ninjas were worthy of God's power, until Flashy Flash slaughtered everyone present before the trial could occur.