Energy acceleration takes many forms in Pokemon TCG. The most classic of these methods are the "Rain Dance" style that started with the base set Blastoise, which are abilities that allow the player to attach as many Energy as they would like of a certain type per turn. Chien-Pao from Paldea Evolved takes it a step further, acting as both the Energy retrieval Pokemon and attacker.
Chien-Pao ex's "Shivery Chill" ability searches for two Water Energy from the deck per turn, as long as it is the Active Pokemon. That is exactly where it would like to be, since its "Hail Blade" attack may deal 60 damage per Water Energy the player chooses to discard from Chien-Pao ex. Multiples of 60 damage is serviceable, as it scales up to modern Pokemon ex's HP with a maximum of six Water Energy.
Late game, the newly reprinted Superior Energy Retrieval renews the stream of Water Energy at exactly the time it is needed - during the endgame.
Water Energy can be attached en masse via Baxcalibur's "Super Cold" ability. It allows the player to attach as many Basic Water Energy from the hand as they would like. While Baxcalibur's Stage 2 status may be alarming, Irida allows Baxcalibur to hit the field as soon as the second turn by searching both the mighty dragon and the Rare Candy needed to bolster its evolution speed. If neither its base form of Frigibax nor its final form are needed, Irida also searches a multitude of utility Water-type Pokemon.
While these Pokemon are familiar as staples in other decks, Baxcalibur's "Super Cold" ability allows them to go a step further and utilize their attacks! Radiant Greninja's Moonlight Shuriken deals two large chunks of 90 damage, enough to remove the likes of Ralts, Kirlia, and Comfey. Even its generally useful "Concealed Cards" ability has synergy with this deck, as Chien-Pao ex guarantees that the player will have access to Energy.
Lumineon V isn't the best Water-type target for Irida - but its Aqua Return attack lets it soak a hit from weaker attacks like Cramorant's Spit Innocently, then return to the deck to further increase Supporter consistency. Late game, this means a higher chance to find Boss's Orders for a critical knockout in combination with Chien-Pao ex's "Hail Blade," or a disruptive move by reducing the opponent's hand size with Iono.
Finally, Empoleon V functions similarly to Klefki in that it shuts down decks such as Lost Box and Miraidon ex. But in this deck, Empoleon V represents more than a stalling tactic - it can tear down opposing Pokemon with its "Swirling Slice" attack! Empoleon V has both higher power and HP than Klefki, but most decks cannot support a 2-Prizer if it cannot attack as well.
The Chien-Pao ex may garner comparisons to the Miraidon ex deck in terms of consistency. While its midrange aspects may be similar, Chien-Pao represents a slower approach, opting not to take KOs on turn two as consistently in exchange for a more diverse set of tools. Specifically, having access to Radiant Greninja's spreading damage is a godsend in a format with many smaller support Pokemon. Chien-Pao ex itself represents consistent explosive damage in a way that no other midrange deck in Standard currently does.