Powerpuff Power Hour

"Powerpuff Power Hour" is the series finale of the Powerpuff Girls reboot. The episode is written by writers of the original series Amy Keating Rogers and Randy Myers. It is a crossover with original 1998 series. The episode is set air on November 18, 2018, to commemorate the original series' twentieth anniversary. The series finale of the reboot leads to a revival of the original series. The episode features Cathy Cavadini, E.G. Daily, and Tara Strong, reprising their roles as their 1998 incarnations.

In the episode, the Professor creates a dimensional portal, in which the Girls enter the 1998 incarnation of their home and meet their counterparts. Meanwhile, Silico is set on destroying the 2016 universe, followed by the 1998 one.

Plot
The Professor finds an old blueprint for an abandoned invention of a dimensional portal (realizing he abandoned the idea as it was unstable). Bubbles peeks above him and tells the sisters about it, which they supplicate him to. A few weeks later, it was finished. The Professor warns the Girls to not use it. However, Bubbles breaks her promise. When the Professor goes to the store, bringing Blossom and Buttercup along, Bubbles stays home and uses it. After turning it on, it sucks her in.

In the 1998 universe of the series, Blossom and Buttercup are re-decorating the house after the party last night. They get interrupted by a crash outside, caused by an unconscious Bubbles from the 2016 universe. Both of the sisters discover it and mistake her as their Bubbles. When she claims that she came from another dimension, they believe that she hit her head after landing, suffering from amnesia. Fortunately, 1998 Bubbles returns from assisting the Mayor. She then notices her 2016 self and exclaims for the Professor.

Meanwhile, the Professor and the sisters come home and find Bubbles absent. Hearing a humming sound in the lab, they discover Bubbles has used the dimensional portal. The girls go to the '98 universe to get her back. At Pokey Oaks Kindergarten, '98 Bubbles shows her other self for show-and-tell. After school, Bubbles befriends her '98 self, though she tells her that her voice is annoying to her response.

Meanwhile back in the 2016 universe, Silico had discovered the Professor's portal from hacking into one of the severance cameras in the lab, giving him an epiphany to destroy the Powerpuff Girls by creating a device to wipe out any dimension from existence. With the 2016 Girls and Professor, they have entered the 1998 universe and find Bubbles. In a montage, Bubbles is guided by the 1998 Powerpuff Girls around their Townsville. Bubbles, the Girls and Professor go shopping at the Malph's grocery store, where the 2016 counterparts find her. Before they bring her back home, Bubbles introduces their 1998 counterparts and persuades her Professor to stay for the night, in which he allows.

Back at the Utonium residence, the Professors engage a conversation on their differences of their respective dimension. The Girls explain their previous adventures to their 2016 counterparts, which interest Blossom and Buttercup in excepting their 1998 selves. The next day, the hotline rings and the 2016 Powerpuffs answer it and get informed that Princess Morbucks has robbed the Bobbin Brothers Jewelry Store (which confuses them as their Morbucks has never done that before). The Girls stop her in time, much to the 1998 Girls' dismay. Called back at the lab, the Professors show them a message from Silico, which informs his plan on destroying the 2016 dimension, followed by the 1998 one. He had already wiped out the Whoopbutt, Z, and 2014 dimensions to prevent them from getting assistance from their other counterparts. Silico arrives in the 1998 dimension and teams up with the villains to keep the Girls from stopping his plan.