no laws in ceres... just cops.
FAQ, under Fukurokuju:
Q: Since he counts as a Stronghold, can Fukurokuju be killed?
A: Yes. The rule that says Strongholds can’t be killed is meant to apply to Stronghold tokens (including the Turtle Strongholds) since tokens can’t be killed (except that the Daikaiju can destroy them). Fukurokuju may commit Seppuku, be killed at the end of a Battle, and be crushed by the Daikaiju. Note that, as a Stronghold, Fukurokuju can be “built” during a Marshal Mandate, if you have him in your reserve.
Emphasis mine. The RAW imply that strongholds cannot be killed, but Daikaiji overrides that. Card effects > base rules.