Legality depends on the tournament format -- Panharmonicon can be legal in some formats and banned or restricted in others
Recommended cards Try having at least three of the following cards in a deck: Doron, Revival Jam, Swords Of Revealing Light, Mammoth Grave Yard, Spellbinding Circle, Pot Of Greed, Pinch Hopper, Insect Queen, Destiny Board, Spirit Message I, Spirit Message N, Spirit Message A, Spirit Message L, Raigeki, Dark Hole, Exodia The Forbidden One, Left Arm OF The Forbidden One, Right Arm OF The Forbidden One, Left Leg Of The Forbidden, Right Leg Of The Forbidden One
The closest thing to any real usefulness is if this card is used with Convulsion of Nature, which flips both Decks upside-down at least its owner can see their top card before they trigger Tainted Wisdom's effect that way
I envisioned a deck that was a cross between Oath and Survival of the Fittest