So is your problem that you can't get the initial project outcome to reveal that the portal leads to the dimension of suffering, instead getting one of the other three options (energy, void, mirror)? Or is it that when you get the suffering dimension result, you don't have the option to pray?
To begin with, I want to say that the Event Hell itself has different text for spiritualists and ordinary empires, and even with the ethics of spiritualism, we get the text from the usual solution. Example:
colony.3006.spir.desc:1 "The Dimensional Portal on [Root.GetName] seems to lead to a realm of evil and disquiet. Any and all contact with material from this dimension causes intense suffering in the subject, which if continued for more than a few minutes leads to intense suicidal urges coupled with attempts to mutilate their sensory organs. Even simply studying data recorded in the strange dimension causes cascading errors in computer systems, or intense discomfort in sapient beings due to the terrifying realization that one's very soul is being corrupted."
And the answer option:
colony.3006.prayer:0 "Pray for a solution" or colony.3006.psi.prayer:0 "Perhaps Psionics is the solution?" (depends on psionic theory)
colony.3006.prayer leads to the event colony.3011 (that gives you psi theory and psi barriers)
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And the Science one :
colony.3006.desc:1 "The Dimensional Portal on [Root.GetName] seems to lead to a realm which is opposed to the sapient mind on a fundamental level. Any and all contact with material from this dimension causes intense suffering in the subject, which if continued for more than a few minutes leads to intense suicidal urges coupled with attempts to mutilate their sensory organs. Even simply studying data recorded in the strange dimension causes intense discomfort in the biological observer, and cascading errors in computer systems."
And the answer option:
colony.3006.science:0 "Find a way to close the Portal!"
colony.3006.science leads to the event colony.3010 (when you gets tech for you districts output)
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Sooo the problem is that in the presence of spiritualism, I still go to the version with science, although I must go to the version with prayer.