Undead status and Near Fatal attacks

Is there a way to make all undead monsters immune to Cyclonic? This would actually be fine in my mod, if it is possible and/or easy to code.

Edit: Wait a minute... I did some testing, and it seems that if I check the box "miss if protected by ailments" for Cyclonic, I can then just set "block near fatal" for all these monsters and it will no longer work. The only downside to this is that Cyclonic will no longer work on any character or monster with the "near fatal" status, but does that really matter? I mean, Cyclonic would only deal minor damage at that point anyway, so who cares if it misses. Am I forgetting anything or breaking anything here?