Ill Omen vs Mythic Iron Will

[Tinalles]

So, suppose a witch casts a quickened Ill Omen (CL 10) on a character with Mythic Iron Will, followed by a Dominate Person.

The Ill Omen spell requires the target to roll twice and take the lower result on his next 3 saves. Meanwhile, Mythic Iron Will allows him to roll twice and take the higher result on all Will saves.

So ... how should this be resolved?

A) Roll twice for the Ill Omen, make a note of the worst, then roll a third time for Mythic Iron Will and take the better of the two?

B) Roll twice for the Mythic Iron Will, make a note of the better, then roll a third time for Ill Omen and take the worse of the two?

C) Declare that Ill Omen and the Mythic Iron Will negate each other's effects, then roll once and take it?

This is very likely to come up in my game on Saturday.

[Jayder22]

Just my interpretation, but I would say

D) Roll 2d20 take the lower and set it aside. Roll another 2d20, take the lower and set it aside. Out of the two dice you took aside, take the higher result.

It seems to me that is how it should work out, though I can see it being read differently. Mythic Iron Will says " Whenever you roll a Will saving throw against a spell, spell-like ability, or supernatural ability from a non-mythic source, roll twice and take the higher result." and Ill Omen says "On the next d20 roll the target makes, it must roll twice and take the less favorable result."

Since the target will be making 2 d20 rolls for 1 save per mythic Iron will, I would assume each of those gets the Ill Omen effect. This does however take 2/3 uses of the CL10 Ill Omen.

[mplindustries]

I would rule it as canceling. That's how 5e handles combining Advantage + Disadvantage and I think it's the most reasonable approach.