Indonesia is made up of more than 17,000 islands, let’s look at one (that’s fake).
In 1942 a FBDACOM (French British Dutch Australian Command) task force consisting of two light cruisers and three destroyers docked at Balikpapan with wild tales of the supposedly uninhabited island of Mantiuana. They claimed to have encountered cannibal soldiers sworn to kill and die for Hirohito and savage tribes that worshiped Golyeong, a mighty gorilla the size of a blue whale with the savage cunning of a man (and a thing for blondes).
Widely dismissed as sailor’s tales, there was one man who believed them, retired Colonel Reginald Braxoton-Smythe who (for the record) made his fortune conducting illegal salvage diving operations and not in industrial tire manufacturing as he claims. Retired Colonel Reginald Braxoton-Smythe mounted expeditions to Mantiuana in 1957, 1959, and 1962, returning with a lurid narrative of a land inhabited by immortal outcast Topará demigods, the descendants of Austronesian explorers, and of course, dinosaurs possessed by Babylonian earthbound demons. Retired Colonel Reginald Braxoton-Smythe claimed that he collected many artifacts from Mantiuana during his visits but they would fade out of existence when taken off the island. This led him to conclude that the island actually inhabited “the Fourth Realm” and therefore could not exist on earth, which is the Third Realm in the Colonels’ bizarre cosmology. As we all know.
Neither the FBDACOM sailors nor retired Colonel Reginald Braxoton-Smythe and his “adventurers” were lying, but none of them ever set foot on Mantiuana either. This is because for many years, Mantiuana was the home of Diane Dream, the Mistress of Illusions, one of the “golden age” heroes of the 1930s. Born Iwalani Haia, “Diane Dream” traveled extensively around the Pacific pitting her powers against the cult of the Dreaming Dark. Her years of thwarting the Dreaming Dark took its toll. Their dark sorcerers also made extensive use of illusions, and living in a world where nothing is what it seemed began to wear on her mentally. In her middle age, she started having trouble with the nature of reality. If someone believes in an illusion, does that make it real? Even worse, she began experiencing episodes of memory loss and possibly memory manipulation. After she found that she was no longer able to conclusively remember what she had actually done and what was illusion, she decided it was time to hang up her cloak and domino mask.
She retired to the island of Mantiuana and used her abilities to keep away any trespassers or interlopers with fantastic mental manipulation. As the years passed, several of her fellow crimefighters came to her seeking solace and retirement on her “invisible island”. They wanted the peace she had found. Her charity proved to be her undoing. Among others, she was joined by her old companions Power Man and Jackknife, who unfortunately were sworn enemies of Baron Iorgu. And the good Baron doesn’t forget his enemies.
The Mistress of Illusion was skilled at keeping away sailors and retired Colonels, but Baron Iorgu was not dissuaded so easily. He led a force of super powered mercenaries and Imperial Japan soldiers (it’s debated if this was an official action or someone’s pet project off the books) to attack the island in 1967. The inhabitants of the island fought fiercely for their lives. They may have been past their prime, but they were some of the most powerful heroes of their age. Problem is, the world had caught up with them.
An old woman with ice powers may be able to kill regular soldiers easily, but if they have insulated suits specifically designed to protect against her abilities, well, then it becomes a sixty-year-old lady with a useless power against a squad of heavily-armed, trained soldiers. Some rare Superman-esque NBH like Angel (god rest her soul) can’t be cracked by copious amounts of airstrikes and heavy weaponry, but them being alive after a naval barrage is cold comfort to the rest that can. Power Man and the majority of the “retirees” on the island were killed. The body of Diane Dream was never found and it’s generally assumed that she escaped and now hides herself behind so many illusions that she can’t be found even by well-meaning old friends.
Once his enemies were dead, Baron Iorgu realized that Mantiuana would be a good place to conduct his maniacal and inhuman experiments in peace and started settling in. No part of the island is shaped like a skull nor is there an active volcano, but hey, you can’t have everything you want in an evil island supervillain lair right?