When this card is Normal Summoned: You can add 1 Spell/Trap Card from your Deck to your hand, that specifically lists the card "Dark Magician" in its text. During your opponent's turn, if you activate a Spell/Trap Card or effect while this card is in your Graveyard (except during the Damage Step): You can Tribute 1 Spellcaster-Type monster; add this card to your hand. You can only use each effect of "Magician's Rod" once per turn.
Magician's Rod gives you many options as to which one to take, and you get to decide which one you need for certain situations. This also helps with getting Dark Magic Attack more consistently, since you can only get 1 copy from Yami Yugi's level up reward.
While a Dark Magician turbo deck can already work well on its own, you can still play with its variances through these support cards. They have different playstyles that are useful in certain situations. Dedication through Light and Darkness can be used as a surprise during battle phase to get an extra attack, Sage's Stone can help with swarming the field, while Knight's Title can be good if your Dark Magician is locked or affected with a attack decreasing debuff.
You can use Magician's Rod's second effect to return it to your hand by tributing these monsters. They have effects that will activate in the graveyard, and will also help with searching a Dark Magician from your deck/graveyard.