I don’t think we really need anything this elaborate.  The Tokyo is definitely a Kaiju God already.  Even if it’s not explicity stated, it is certainly implied just about every time “Tokyo” appears (most notably in the first sentence of Rule 1.9).

If you’re worried, I think it would be best to simply change “Each Dynasty is headed by a single Tokyo” into “Each Dynasty is headed by a single Kaiju God, known as the Tokyo”.

Implication is fine, but if you turn it around, I think that a very strong CfJ case could be made to prevent Tokyo from doing just about anything in future. Rule 1.9, for example, does not make clear whether the Kaiju God assumes the role of Tokyo, in which case remains a Kaiju God, or becomes Tokyo, in which case becoming a seperate class altogether. Perhaps there is a more elegant way of preventing this, but I do not think that actually making it explicit is actually a bad thing.

Odd, we must just have lost that somewhere along the way. Hix’s wording is much easier, and this sounds more like “urgent attention” CfJ territory than anything. I’ll put one up.

due to the existing CfJ.

Self-kill, as the CfJ does it better.