Why can't they make the Kaijujin playable characters? They just need to make them weaker, smaller and more balanced so they can be played as... it's been done a loooooot of times in other games, like TimeSplitters 2 and.... .... TimeSplitters: Future Perfect.... and lots of others. I think they should be playable. Not being able to play as NPC's socks...
The reason they are "gods" is because when ever a kaiju is being made, they are there trying to make the kaiju equal size and strength including power to make the fight "interesting" for they own amusement, in fact, what I read was that the reason they exist is only because kaiju exist...it seem like King Ghidorah made them since he was the first to be made since he live forever.
Impressive looking creature. She is simple in form, a raging fire monster, and since she is just an NPC that represents a faction of a Kaiju's personality, and represent power ups and quests during the game.
Now, they say the Kaijujin are responsible for the state of all Kaiju. If one knew about them, one might think it a smart idea to try and take them out if one could. But that would be incredible folly, and one should just deal with each Kaiju as one comes across it. It would be like trying to stop a war in Ancient Greece by seeking out and trying to stop or destroy Ares. Besides, you said it yourself, they didn't create the concept o Kaiju, they just exist because Kaiju exist, they didn't create them, they just regulate them. To be rid of them they could go out of control and any balance of power they had among all Kaiju would be lost.
Yes, my kaiju Xeraimus will be a playable character eventually. First things first I have to go through the collaboration process which won't be happening for awhile now possible three or four months from now.