Throughout the show there is a theme of three that pops up quite a few times. The show refers to it as the Triangle. It shows up in more ways than one but for now, lets talk about how it shows up in regards to the characters. It is referenced a lot in regards to Jan, Retsu, and Ran so we might as well start by looking at them and the current Triangle of Heart, Body, and Technique. I'll cover the other times the theme shows up as they appear.
The Other Kensei: The Kensei are all pupils of the founder of Jyuken: Brusa Li. Originally Brusa Li had ten students, seven became the Kensei and the other three rebelled. Those three became the Kenma, RinJyuken's founders. There is also a Triangle among the Kensei which is introduced during the Kageki arc. Its the original Heart, Body, and Technique Triangle formed by Gorie Yen (Heart), Michelle Peng(Technique), and Pyon Piao (Body). Jan, Retsu, and Ran have to undergo Gorie, Michelle, and Pyon Piao's trials in order to gain access to Kageki. The Kageki arc is great because we get to see the Jan, Ran, and Retsu take on each of their weaknesses by facing off against the Kensei triangle. The Kensei's names are all references to martial arts film actors. I particularly love how the show keeps bringing these guys up even after their introduction. Even though they're technically side characters, they still feel like a major part of the show and they even have a major impact near the end.
Suits: This is going to work a little differently since its a three part review. I'll cover the Gekirangers' suits here and cover Rio and Mele's suits in the RinJyuken portion of the review.
Jan, Retsu, and Ran get Super Gekiranger modes that are accessed through using the Super Geki Claw developed by SCRTC alongside channeling their Kageki. The torsos become white and the claw insignia turns into each of their colors. The spots and stripes on their suits turn into jets that allow for flight. The helmets also get these nice white highlights on them. I really love the color balance on these suits and the white complements them really well.
Mecha: There are quite a few mecha in this show. However, a lot of them are auxiliary GekiBeasts so I'll just cover the main mecha combinations to keep this from running on too long.