I have to make peace with you for the sake of the results, unpleasant as you are. I don't know if this solution would work. I'll take suggestions from any corner. The whole mechanism implements disbelief. It works in the following way for the illusionary weapons of phantom warriors:
Spell 1, save. vs. spell: blocks spell 2
Spell 2, no save: Protection from Gender: Illusionary
When a creature is struck by an illusion, it by default becomes immune to that Gender, unless it fails a saving throw against the spoiler spell that prevents this from happening for a round. More powerful creatures and wizards have better chances to save and so more often disbelieve. The protection itself comes in a round later. In the first round there is only doubt, and the phantom warriors can still strike with their spears, though phantom damage only lasts a round. Then hit points come back and the creature gets another chance to disbelieve as the spoiler spell wears off. With Phantasmal Killer, however, which is what I'm working on now, protection had to be immediate and include immunity to the effects of the hit, because a phantasmal killer kills if it lands a blow. The system here looks like this:
Spell 1, save vs. spell: blocks spell 2
Spell 2, no save: blocks spell 3 + Protection from Illusionary
Spell 3, no save: kills
And here is where I want to insert a Self-targeted Remove Creature effect, because a phantasmal killer only gets to kill once, in my interpretation anyway. But if I put somewhere above, in Spell 2, a Self-targeted protection from Spell 3, as you, subtledoctor, propose, then the removal in Spell 3 also will not happen. In other words, I want it both ways: for Spell 3 and everything in it to be blocked completely if the target succeeds in saving, but also for all of the effects to take place if the save attempt fails.
