You cannot activate this card's effect if you treat it as a Spell Card unless its destroyed by opponent's card effect and sent to grave; it remains face-down on the field until its from the field. It can be a great decoy to lure your opponent into wasting their Spell & Trap Card Zone destruction cards before their big play or convincing your opponent to fire off the effects of "Judgment Dragon", "Demise, King of Armageddon", "Mobius the Frost Monarch", etc unnecessarily.
If you're prepared for it, this can also lead into an excellent "Honest" counter-attack if your opponent attacks "Toy Magician", as many players do not see this card used often and an aggressive player may disregard its LIGHT threat potential.
As a LIGHT Spellcaster monster, it can fit nicely into Chaos or Twilight specific Spellcaster Decks.
Combined with "Wonder Wand", you'll be able to turn it into a 2100 ATK monster, draw two cards when required and load up your Graveyard for a "Chaos Sorcerer" or "Black Luster Soldier - Envoy of the Beginning" Special Summon.
A nasty (but admittedly situational) tactic is to use this card in a deck running "Secret Village of the Spellcasters" and "Royal Decree" to fool your opponent into wasting Effect Monster spell/trap destruction options on your "Spell & Trap Card Zone" to get easy special summons of "Toy Magician", while maintaining the requirement for "Secret Village of the Spellcasters".
This card can work well in combination with "Magical Dimension" to special summon a stronger Spellcaster-type monster by surprise after your opponent destroys this card while it is face-down in the "Spell & Trap Card Zone".
As a bonus you'll also potentially destroy one of your opponent's monsters too off "Magical Dimension's" second effect, which can't be stopped by "Stardust Dragon" as it is an optional destruction effect.
This card works very well in an "Artefact" Deck.