* HeyItsThatGuy - Shuji Mihara is [[Series/RescueSentaiGoGoFive Go Green]].
** And in Paradise Lost, Creator/ShozoIizuka, Creator/GoroNaya, and Creator/KatoSeizo all make appearances as the three executives behind Smart Brain.
** Smart Lady was Shimada from [[Series/KamenRiderRyuki the previous series]].
** The young version of Mari Sonoda was Creator/AoiYuuki. Yep, [[Anime/PuellaMagiMadokaMagica Mari is a magical girl.]]
** Apparently [[{{Garo}} Rei Suzumura]] was an Orphenoch before becoming a Makai Knight.
* NamesTheSame: Naoya Kaidou shares a family name with [[{{Tsundere}} Kaoru Kaidou]] from ''ThePrinceOfTennis'' - who, funnilly enough, has the nickname "Mamushi" (Viper) whereas ''Faiz'''s Kaidou is the Snake Orphenoch.
* WhatCouldHaveBeen: There are few elements that never made it to final production. Like [[http://images.wikia.com/kamenrider/images/6/6f/Rejectfaiz.jpg three unused riders]] and Kaixa's equivalent to Faiz Accel, [[http://images.wikia.com/kamenrider/images/7/73/913break.jpg Kaixa Break]].