Interactions that target creatures have [IT_LOCATION:CONTEXT_CREATURE] rather than[IT_LOCATION:CONTEXT_REGION].
Second, looks like regional interactions work with [IE_INTERMITTENT:WEEKLY] only, [IE_IMMEDIATE] isn't supported.
Finally, if else fails, my test regional interaction had [IE_ARENA_NAME:].
Greatly thanks!
IT_LOCATION:CONTEXT_CREATURE worked, along with IE_INTERMITTENT:WEEKLY. All stray animals, wild animals and embark team is slowly transformed into cats, one by one.
Strange, but when all of citizens transformed into animals, game doesn't stop
interaction_test
[OBJECT:INTERACTION]
[INTERACTION:TEST_REGION_INTERACTION]
[I_SOURCE:REGION]
[IS_REGION:ANY_TERRAIN]
[IS_FREQUENCY:100]
[IS_REGION:NORMAL_ALLOWED]
[IS_REGION:EVIL_ALLOWED]
[IS_REGION:GOOD_ALLOWED]
[IS_REGION:SAVAGE_ALLOWED]
[I_TARGET:A:CREATURE]
[IT_LOCATION:CONTEXT_CREATURE]
[IT_AFFECTED_CLASS:GENERAL_POISON]
[IT_IMMUNE_CREATURE:CAT:MALE]
[I_EFFECT:ADD_SYNDROME]
[IE_TARGET:A]
[IE_INTERMITTENT:WEEKLY]
[SYNDROME]
[CE_BODY_TRANSFORMATION:START:0]
[CE:CREATURE:CAT:MALE]
maybe I added too much IS_REGION's, but I wanted to make that sure.
Btw, is there any way to customize announcement that is printed when syndrome is applied? Found only CE_DISPLAY_NAME, that change name of creature.