When you Ritual Summon a monster, you can banish this card from your Graveyard as 1 of the monsters required for the Ritual Summon. If the monster Ritual Summoned using this card destroys a monster by battle, the controller of the Ritual Monster draws 1 card.
Can be used as ritual fodder while in the graveyard.
Lets you draw cards.
Effect can only be used alongside ritual monsters which can be difficult and costly to summon.
Decks like Cyber Angel, Gishki, etc. have their best monsters as ritual monsters. Djinn Presider of Rituals can be used as ritual material in the graveyard to ease the cost for these decks. And since their boss monsters are already powerful monsters, they will have no problem attacking over other monsters, destroying them, and drawing a card.
Relinquished is a level 1 Ritual monster making him very easy to Ritual summon. One Djinn Presider of Rituals in your graveyard could fulfill the cost for his Ritual summoning.
Some Ritual monsters like Vennu, Bright Bird of Divinity and Saffira, Queen of Dragons are already great for gaining advantage. Use Djinn Presider of Rituals to summon them so they can become even better advantage gaining engines.