The Shadow, The Green Lama, and Doctor Strange.
Lamasaries in pulps and comics did a thriving business in training Westerners who crashed on, stumbled into, or sought out their mountaintop locales to receive physical and / or mental training which they then used to fight evil back in their homelands.
(Oddly enough, very few Asian characters bothered to go to the Himalayas to learn mystic or martial arts! But I digress...)
A rich, but disillusioned, American who had spent over two decades living in Tibet, seeking enlightenment from the monks, learned the lamas' secrets of "ultimate control of their mental processes."
Returning to the USA, he took a new civilian identity, "Phil Anson", and began a war on crime as Phantasmo! (We never learned his original name or why he was so disenchanted with his previous life.)
Like The Spectre, Phantasmo was actually an astral projection who could take solid form when separated from his "host" body.
His abilities included super-strength, flight, near-invulnerabilty, and penchant for growing / shrinking tricks.
Also like The Spectre, Phantasmo wore just shorts, boots and a cape. (astral bodies apparently don't get cold.) Unlike The Spectre, who wore green, Phantasmo wore yellow with gold highlights. This had the unfortunate side-effect of making him look like he wasn't wearing anything at all if the Magenta printing plate got screwed up, which happened from time to time! (Warning: NSFW)
While his astral form ran around doing heroic feats, his human form was unconscious and helpless. Phil hired Whizzer McGee, a bellhop at the hotel Anson lived in, to guard his body while it was "unoccupied".
Debuting in The Funnies #45, Phantasmo was the first superhero character from Dell Comics, who had previously done reprints of newspaper strips like Dick Tracy.
From his premiere, Phantasmo was the cover feature of The Funnies until #57, when he shared the cover with up-and-coming superstar Captain Midnight, who forced him off the cover as of the next issue!
"The Master of the World" remained as a backup feature until #63, when The Funnies became a funny animal book and Captain Midnight got his own title.
Phantasmo literally disappeared for several decades, until revived (in flashbacks) in Alex Ross' Project SuperPowers mini-series a year or so ago!
We suspect he'll be showing up in the present-day storyline, in due course.
In the meantime, we're re-presenting him on a line of kool kollectibles including t-shirts, mugs, messenger bags and other nifty tchochkies.
So, check out "The Master of the World", as Phantasmo was described on the covers, before he catches a cold. ;-)