Sam Archer: Private Investigator, Degenerate Serpent Cultist, Feasting Ghouls, Fledgling Byakhee, and the heroic Harry Houdini!

The Cave on the Hill isn't too sneaky. Opponent knows it's there but is uncertain about over-commiting and diminished offense next round. Almost as good as two characters though, if played right. Spreads the defense with offensive bluff for attack on a second story.

But how to use it more than once a phase?

That's creepy. Wikipedia puts Houdini's death in 1926, two years before CoC's timeline. Maybe he's a restless spirit out for blood?

Houdini may be the most vital Lovecraft real person to grace the fictional mythos, his short story submitted to Lovecraft totally ghost rewrittten by Lovecraft.