The Starlight Illusion Array is a powerful magic formation created in ancient times. According to the rankings of powerful magic formations by William the Obliterator back in the day, Poseidon's Godslayer Array ranked fourth, while the Starlight Illusion Array was second only to Odin's Gungnir Stellar Array, which took the top spot.
This is precisely why Odin and Uranus dared to join forces and confront Zeus's Divine Alliance.
Of course, another reason was that the Cosmic Entity didn't want any single power to dominate.
Regarding the rankings of powerful magic formations, it was also because William found the dazzling effects of the Gungnir Stellar Array more interesting. It's tough to rank them strictly by strength.
Anyway, the Starlight Illusion Array is also considered a famous offensive magic formation from ancient times.
