Why does this thread upset me so much? I'll put that aside for now though.
I believe Garulu is the sound made by wolf and dog like monster in the minds of the Japanese, so they often use it for wolf and hound themed abilities and characters. Garurumon from digimon is cut from the same cloth, if I remember correctly. Bassha and Dogga probably act the same way with their alternate forms and weapon names representing the sounds that correspond to them. In a show that has music and sound as a general theme, it makes sense.
The reason we got Emperor as early as we did is quite simple: The base form was the most uncomfortable suit Seiji Takaiwa had worked with up to that point. The fiber glass was extremely heavily and hard to work with, while the Emperor form suit was alot more comfortable. That is why after Wateru gets that form in show you rarely ever see base form anymore.
I love the design of all the Kiva riders except Arc. They have simple, but very gothic feels that really tickles my fancy as a fantasy buff. They are simple, but unique, and suit their users quite well.
I am even a fan of the belt swaping with IXA which shows that the protoype could only be used by exceptional users while the updated version could be used by anyone. This meant that when someone lost with IXA in modern times that it wasn't the system, but the user, which proves that just slapping on the belt isn't enough to win. As for his fake fuestles, I figure we got no explination for them because it was pretty obvious what they did: mimiced Kiva's fuestles to intercept the arms monsters for his own use. I admit these didn't get alot of use in series but if you think about it that makes sense. Kiva now knew IXA had the ability and how much it hurt. The Arms Monsters now knew IXA could trick them into coming to his aid, so they would be more cautious about deploying. You want to blame someone for Kiva not useing his alt. forms more often, then blame IXA for being a hard ass. It was a great stradegy for limiting Kiva's options in battle.
Saga could have had more, but he really didn't need it. He was a late series rider, but even he got some neat stuff like a badass finisher, an army of Sagarcs, and Kukulkan the flying serpant monster. All this before he ever gets his answer to Emperor form: Dark Kiva.
Dark Kiva's finishers are some of the best and most flexiable in rider history. He didn't "forge" the arms monsters to use them as weapons; he did it to make them his trophies and possiably for Taiga to use. Dark Kiva had everything he needed with his three different finishers, which also acted to show just how much more power and control he had then Wateru. The armor also totally screamed "I'm a dark lord bent on destroying your ass...now die."
The Fangire sireing more fangire was featured in Decade with Super Apollo Geist which means under certain circumstances it can happen. The Fangire were a very proud race though who often saw humans only as a food source. Would you want the ability to turn a chicken into a human? Okay that may have been a bad example, but you get my point. They may have had the ability, but chose not to use it. Also if you were a life eating vampire monster, would you really act like it? No, you would probably try to fit in as much as possible as not to draw attention to yourself. Especially with Kiva and IXA running around killing your buddies who do eat people. Then again that cute girl does sometimes show up instead...though she does whip you with a bladed chain sword.
Anything else for me to rant about? No. Good, then I'll rant more later. Kiva may not have been a perfect series, but it was still a notch above most others in my book.
