Metamorpho 16 (Jan/Feb 68) is my favourite issue of the entire run. Bob Haney and Sal Trapani launch a multi-issue storyline that would not, unfortunately, ever be completed.
The story begins with a shocker, as Sapphire Stagg marries Wally Bannister. Java is despondent, but Simon Stagg is thrilled, and we learn that Bannister is also very wealthy, and Stagg views this more as a merger than a marriage. Sapphire is not terribly happy, either, and thinks that Metamorpho didn't even come to bid her farewell as she sails off on her honeymoon, though in fact she just didn't see him,
Element Girl figures that, with Sapphire now married, Rex will be all hers, but he has changed his feelings again, and calls things off with her. When the mysterious Mr. Shadow shows up to enlist Metamorpho in a hunt for a lost city, the hero is eager to go. Simon Stagg tries to use the Orb of Ra to stop him, but Element Girl intervenes and takes it, allowing Metamorpho to leave.
Mr. Shadow wants the hero in his Rex Mason identity, although why he demands this is far from clear. They fly to the lost city, which Mr. Shadow knows the exact location of, and once there, he reveals Metamorpho's appearance to the people.
They are ruled by Queen Jezeba, who happens to look identical to Sapphire Stagg. She, like the others in the hidden city, is much older than she appears. She believes Metamorpho is her long lost love, Algon,who was an element man back at the time of the pharaohs.
Jezeba wants to marry Algon. Metamorpho is upset enough about losing Sapphire that he decides to go along with it, figuring pretending to be someone else is worth marrying a Sapphire lookalike. Jezeba turns out to have a vast arsenal, and plans of world conquest.
Despite the marriage, Metamorpho knows he cannot go along with Jezeba's attack. He takes command of her army, only to lead it into a death trap. Jezeba is furious, and turns out to have a second Orb of Ra. When she tries to use it against Metamorpho, she winds up aging instantly, and dies.
As the story ends, Mr. Shadow winds up in possession of the second Orb of Ra, putting him in command of Metamorpho.
The story continues in the next issue.