This card is a great counter to Pendulum Summon plays, as she can force the opponent's Pendulum-Summoned monsters to attack her, and if so, will guarantee them to die (and can give you bonus cards). She could also be equipped/supported with certain cards to make her unkillable via battle, so she'd be potentially able to wipe out an opponent's entire field that they just Summoned.
Likewise, you can simply run her with your own Pendulum deck for an easy 2100 Atk 4-star attacker with no particular downside, along with any buffing she could potentially get from your own Pendulum Zone cards.
This card is a level 4, psychic-type, WIND Attribute effect monster, allowing for good synergy with Psychic and Gusto decks.
If your opponent doesn't have Pendulum Monsters in their Deck, you may be able to trick them into using your own by using "Gift Exchange". It also has the added bonuses of removing a card from your Deck at seemingly no cost and having some knowledge of what your opponent is playing, while potentially powering up "Hypnosister" in the process.