Super Sentai series titles : some recurring Kanji

Hello guys, it's been a while since I've written here; I had trouble finding ideas to write a new blog post.
However, today, I've been thinking about the sentai series franchise : 40 years, 39 series and a 40th series to come soon.
As you know most sentai series have a title involving three words : a specific word written in kanji, different for each series, involving usually two, but sometimes one or even three kanji, followed by "Sentai" and then, a third word in katakana, being the name of the team, including either "man", "ranger" or its short form "ger", or even sometimes, "Five".
I've investigated the kanji used in the first part of the title (or those used outside of either "Sentai" or the katakana in the few series not including "sentai" in the title, such as Bioman or Flashman)). Because Super Sentai often uses the same themes, it often uses the same kanji in different individual series titles, and I've made a list of the kanji that appear in at least two titles of sentai series.
And here are the results : 

The kanji appearing the most, with six sentai series titles is the kanji 電 (den), the kanji meaning "electricity" : it appears in JAKQ, Denziman, Bioman, Changeman, Megaranger and Kyoryuger : it has been used in different contexts : either, it reflects a technology theme involving electronics, such as in Denziman, Bioman and Megaranger, and in a lesser way, Kyoryuger, with the dino theme associated with a "battery" theme. Or it is used in combination with the kanji "strike" (geki), to mean a "sudden attack", meaning that the team strikes quickly and hard, such in JAKQ and Changeman. The kanji started being used very early, since it appears in JAKQ first, the second series, and most of the series having it in the title are pretty early, (4 out of 6 in the first 10 shows) ; however, it has been used pretty recently too, as seen with Kyoryuger. Of course, "Den" is also included in katakana in Denziman.

In second place, with five titles, is the kanji  獣 (Juu),  the kanji meaning "beast" : it appears in the titles of five series : Liveman, Gingaman, Gaoranger, Gekiranger and Kyoryuger : it's pretty expected since animals is a theme used very often in sentai, and predictably, the five series have an animal theme (even if Kyoryuger has the more specialized theme of dinosaurs) ; besides, it's obvious that Zyuranger and the upcoming Juuohger also have in katakana actually the same meaning. It's interesting that, while used frequently, the kanji started being used relatively late in the franchise, starting with Liveman,  when animals started becoming a major mecha theme.

In third place, is the kanji 超 (Chou), meaning "Super", used four times, (in Bioman, Flashman, Liveman, and Ohranger) : interestingly, it's especially used in series not including "sentai" in the title, since among the four series, two of them don't include sentai (Bioman and Flashman) ; that kanji isn't unexpected, since we're talking about superhero shows titles (we're talking about Super Sentai). Thus having sometimes "super" in the titles of some shows is pretty logical. Interestingly, most of the shows having it in the title are 80' show in a short span (the golden Soda age), with Ohranger being the exception (and even that one has Soda heavily involved)

In fourth place is the kanji 星 (sei),  meaning "Star" included in three titles (Flashman, Dairanger and Gingaman) : interestingly, the series having it in the title aren't especially space themed, with the exception of Flashman, which has a major space theme : Dairanger has a martial arts, mystical beast and Chinese theme, while Gingaman has an animal theme, with the only "spatial" elements being the origin of the villains, and of the mechas : but having the kanji "star" in the title gives a sense of large scale in the show's universe, since it goes beyond Earth to include the whole universe.

Interestingly, those kanji are often associated with each other :
"Juu" is associated with "Den" in Kyoryuger, "Chou" is associated with "Den" in Bioman, "Sei" in Flashman and "Juu" in Liveman, and "Sei" is associated with "Juu" in Gingaman.

Several kanji appear twice, often in series with a same theme :

忍 (nin), meaning "stealth" appears in two ninja themed shows titles, Kakuranger and Hurricanger, and of course, it's in katakana in the title of the third ninja themed sentai title, Ninninger

Similarly, 竜 (Ryu) meaning "Dragon", is included in two dinosaur themed sentai show titles, Zyuranger and Abaranger (Kyoryu means dinosaur (terrible dragon), and of course it's in katakana in the third dino themed sentai title, Kyoryuger.

Another kanji, 特 (toku), meaning "special", is used in recent shows having a professional team included in an official organization involved in fighting the enemies : Dekaranger (the police sentai) and Go-Busters (the special Energy Management Center). It's interesting to notice that the kanji has been used a lot in the Metal Hero franchise, also involving professional teams (notably in the Rescue Police shows, which Dekaranger pays tribute too)

Two kanji are used twice, and always associated with the kanji "Den" : it's "子"(Shi), which usually means "child", but here is used with "Den" to mean "Electronic, in the titles of Denziman and Bioman ; and the other "撃" (Geki), meaning "Strike", used in JAKQ and Changeman with "Den" to mean "lightning strike", "Blitzkrieg", a very quick sudden and effective attack : it's however likely that kanji that appear in Katakana in "Gekiranger", which has a martial arts theme involving "strikes". 

In a word of conclusion, the kanji 轟 (Go) is used twice in the same title, the title of Boukenger, to have both the pun of the english verb "go" showing the "adventure theme" and the "loud explosive sound" which is the true meaning of the kanji, which means to show how that adventure team is full of energy. 

It's more than likely that future sentai shows are either gonna have those kanji appear again, or having kanji that have appeared so far only once appearing again. 

Your thoughts?