Following are a number of back-translations of Revelation 18:21:

• Uma: “After that, a strong angel lifted a big stone, bigger than a rice-mortar, he threw it into the sea, he said: ‘Like this stone is thrown into the sea, and is no longer found again, like that also the big village of Babel will be destroyed all-at-once, it will no longer be built again.” (Source: Uma Back Translation)
• Yakan: “After this, there was a very strong angel, he grabbed a very huge stone like a millstone, and he threw it in the sea. He said, ‘Like that also will be the force of ‘fragmentation’/making into fragments of the famous city of Babilon and it will never, never be seen again.” (Source: Yakan Back Translation)
• Western Bukidnon Manobo: “And then there was a powerful angel who lifted a stone as big as a stone grindstone, and he threw it into the sea, and he said, ‘Like this the great city of Babylon has been thoroughly destroyed. It will never again be seen by anyone.” (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: “After-that there was a strong angel who hefted a large stone like the largest mortar, and he threw it in the ocean saying, ‘Like this is what will happen to the great city Babilonia, because it will be thoroughly destroyed and will not again be erected.” (Source: Kankanaey Back Translation)
• Tagbanwa: “And then there was a far-from-ordinary angel who fetched one rock which was really big. He threw it into the ocean, speaking at the same time, saying, ‘Like this is the force of the destruction of the famous city of Babilonia. It will really never be seen again.” (Source: Tagbanwa Back Translation)
• Tenango Otomi: “Then an angel, who was very strong, picked up a large stone that was very heavy, like a milling stone. He threw it into the sea. And he said: ‘Just like the stone here now cannot be seen, it will be like this concerning the city of Babylon. It will never be seen again.” (Source: Tenango Otomi Back Translation)