Immigration condition

■basic requirement

hospital is not requirement,  so you can put troop in the hospital to decrease power a bit.

■season

- only to offseason 

- there is some limitation.  like this (I just make table from the screenshot below. not so sure if this table is aqurate)

this means,  I guess,

can NOT go forward to older kingdom (to prevent to get new commander?)

can back to newer kingdom,  but can not go back to season1

to season of conqueset

to season3

to season2

to season1

■the number of passport required

see https://rok.guide/immigrate-kingdom/