When it comes to '90s revivals, fans have to agree that Mighty Morphin Power Rangers: Once & Always completely delivered. The one-hour episode brings back fan-favorite characters, emulates the original tokusatsu vibe of Power Rangers perfectly, and treats the fans to many references to the 30-year-old franchise.

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Most of the series' Easter eggs pay homage to the first show, Mighty Morphin Power Rangers. However, Once & Always also includes references to other Power Rangers series and even the comics. Only those who have followed the franchise for years will notice them.

10 The Meaning Of Zack Becoming Minh's Guardian

Billy, Zack and Minh pose in front of the RadBug in Mighty Morphin' Power Rangers: Once & Always.

From the beginning, Mighty Morphin Power Rangers: Once & Always establishes that Zack became Minh Kwan's guardian after Trini's death. Throughout the episode, he acts like her only parental figure, and Minh even comments that he abandoned his congressman career to raise her.

This may have seemed like a normal thing for casual fans, considering how close all the Power Rangers were. However, comic readers know that it's a bit more than that. In the comic series, Zack and Trini are an actual couple for a while. In a way, having Zack take care of Minh honors the family he and Trini could have together.

9 The RadBug 2

Zack, Billy and Minh riding the Radbug2

Throughout the episode, Zack, Billy, and even Minh use a blue Volkswagen bug as transportation. This car, although vintage, has been enhanced with different types of technology. In fact, in a very obvious callback to the '90s science fiction tropes, it flies.

The RADBUG2, as stated on its plate, is the newest version of one of the best Power Rangers inventions ever. The RADBUG, or Remote Activated Drivingzord for Basic Ultra Geomorphology, was invented by Billy after the team lost their teletransportation abilities. The RADBUG2 is a fun callback to the original series.

8 The Bandora Protocol

Robo-Rita Repulsa appears in Power Rangers Once And Always

After the death of Trini in the hands of Robo-Rita, the Rangers created a contingency plan in case the villain returned: the Bandora Protocol. This plan included Power Rangers from all over the world, who received a distress call after Alpha 9 activated it.

The Bandora Protocol was created for Once & Always. However, its name is a reference that only true Super Sentai fans will recognize. Bandora Witch, or Majo Bandōra, is Rita Repulsa's counterpart in Kyoryu Sentai Zyuranger, the 1992 tokusatsu series from which Mighty Morphin Power Rangers took a great deal of footage.

7 "Together They Are More"

The cast of the Power Rangers movie from 2017 posing for promotionals

Around the 31-minute mark, while Robo-Rita rejoices by seeing how many Rangers she has captured already, she drops a sassy line: "It's funny. I never believed in their whole teamwork thing, but together, they are more. More power for me, that is." This isn't just Robo-Rita's way of mocking them; it's also a reference to the franchise.

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"Together we are more" is the motto of the 2017 film Power Rangers. The film, which serves as a Mighty Morphin Power Rangers hard reboot, includes the phrase in the promotional posters and focuses on its meaning by showcasing the Rangers' teamwork. Although Power Rangers was a Box Office Bomb, it's nice to know the creators still honor it as part of the franchise.

6 Harvey Garvey's Tombstone

Power Rangers at the Harvey Garvey's Talk show

During Robo-Rita's ambush at the graveyard at the beginning of Once & Always, the remaining Rangers fight Snizzard and Minotaur, two of the strongest Power Rangers villains ever. After Zack joins them, there's a small moment where the camera focuses on a tombstone for Harvey Garvey.

This is a very sneaky easter egg. Harvey Garvey is the host of The Harvey Garvey Show, a talk show that had the Rangers as special guests in the hilarious 33rd episode of the second season of Mighty Morphin Power Rangers, "Lights, Camera, Action."

5 The Troobian Empire From Power Rangers S.P.D.

The leaders of the Troobian Empire in Power Rangers SPD

Once & Always surprised the fans by expanding on the Power Rangers lore beyond the Mighty Morphin team. For instance, it brought back Aisha Campbell and Adam Park — former Yellow and Black Rangers, respectively — but it established that they now work as members of the Space Patrol Alpha, fighting the Troobian Empire.

Fans of the franchise surely immediately recognize the implications of Aisha and Adam's new team. The Space Patrol Alpha team comes directly from Power Rangers S.P.D. In fact, the Troobian Empire was the main villainous group of this Rangers generation.

4 Benny Joy Smith As Annie

Benny Joy Smith As Annie in a cellphone reporting about Putties at the Juice Bar in Once and Always

Mighty Morphin fans may have caught most Easter eggs referencing classic moments from the franchise. However, only those who keep tabs on the modern series recognized the woman reporting the Putty attack at the Juice Bar on Minh's screen around the 17-minute mark.

This journalist's name is Annie, and she's portrayed by Benny Joy Smith, a regular character in the 2021 Power Rangers show Power Rangers Dino Fury. Her small cameo in Once & Always is yet another way in which the show recognizes the whole franchise and establishes all generations as existing in the same universe.

3 Kat's Pink Ranger Bow

Katherine Hillard morphs into the Pink Mighty Morphin Ranger

The Rangers summon their canonic weapons during the final battle against Rita on the moon. To the fandom's delight, Minh uses Trini's Power Daggers, Rocky uses the Power Sword, Zack wields the Power Axe, Billy fights using the Power Lance, and Kat even shoots Rita with the Power Bow.

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True fans surely noticed this last detail immediately, as it marks the first time Kat used the Power Bow. In the original series, only Kimberly wielded it. Kat never used the Dino Powers. Instead, her animal was the crane. It's impossible to know if this was a continuity error or simply a way to pay homage to the original character.

2 Aquitar & Other Iconic Locations

The Alien Rangers Of Aquitar posing for battle in Power Rangers

After 30 years, the Power Rangers franchise has created a whole universe where all teams coexist, even if they don't collaborate often. This world-building is one of the best things about the series. To the fans' delight, Once & Always had it in mind. The episode is full of references to the Power Rangers universe.

For example, when Alpha 9 activates the Bandora Protocol, the screen shows the names of different cities, such as Reefside, Turtle Cove, and Coral Harbor. All these locations reference different Power Rangers series. Additionally, Aisha and Adam invite Billy to Aquitar, the planet of the Alien Rangers.

1 Billy's Comment On Zord's Being A Second Nature

The Rangers in the Zord's cockpits

In the climax of the episode, once Minh embraces her role as the Yellow Ranger, she has to learn how to use the Megazord. When questioned, Billy's only advice for her is to do the same thing as he does, but additionally, he tells her that she will "find it second nature."

This casual comment is actually a callback to Billy's reaction during the first-ever battle using the Dinozords in "Day of the Dumpster." When the original Rangers first drove their zords, they commented on how easy it was. Billy says: "It's almost like second nature to me." Only those fans with great memory may have noticed it.

NEXT: 10 Best Classic Power Rangers Episodes, Ranked