Harpie Lady is one of those fair decks that are only able to synchro/XYZ summon one monster per turn, but, at the same time, has access to one of the most broken cards in the game in Harpie's Feather Storm, which, because we actually play Harpies and not some toxic stuff like Floowandereeze, we can activate it from our hand at quick effect speed, meaning that a single Harpie monster can mean stopping the opponent's turn or protecting ourselves from handtraps or being able to break the opponent's field more easily during our turn; we can either hard-draw one of our 3 copies of Feather Storm, set it directly from deck with Trap Trick or search it during the end phase with Hysteric Sign's effect, which is triggered if it's destroyed by something like Harpies' Hunting Ground or by the opponent, or used as cost for something like Forbidden Droplet or Knightmare Phoenix (Remember that Hysteric Sign's search 3 effect can't be used if its effect to search for Elegant Egotist was activated that turn). Our optimal turn 1 play is the following: Cyber Slash Harpie Lady plus Feather Storm, waiting for the opponent to summon and activate a monster effect and then activating Feather Storm, stopping their monster effects and this way Cyber Slash's effect also activates returning an opponent's monster to the hand, setting them back even further. Our optimal turn 2 plays are the following: with the support from cards like Feather Storm, Feather Duster and Forbidden Droplet, XYZ summon Number 39: Utopia Double to deal up to 10K battle damage on monsters or summon Zoodiac Chakanine into Zoodiac Boarbow to go into a 4 material Divine Arsenal AA-ZEUS - Sky Thunder.