Mirror Abilities

[Ming]

Some abilities change the rules for specific models. But what happens, when two identical models become opponents? Here are a few examples:

Hanged's Forever Doomed: 

This model treats any Black Jokers it flips or Cheats as Red Jokers. Enemy models treat any Red Jokers that they flip or Cheat in opposed duels with this model as Black Jokers.

What happens when two Hanged models flip jokers against each other?

Pride's Solo:

Until the End Phase, friendly models within range always Cheat Fate after enemy models in opposing duels.

Who cheats first, when two Solo auras overlap?

There's a precedent in Mourner's Mourn the Dead:

Until the Start Phase, Corpse Markers within range are treated as friendly Scheme Markers. If a Corpse Marker counts as a friendly Scheme Marker for both players, it does not count as a friendly Scheme Marker for anyone.

Should the "negate each other" principle be used as default?

[solkan]

There's pretty much no other way to resolve effects like Pride's Solo Action's non-Condition other than to have them negate each other.

Note that the Mouner's Mourn the Dead is the opposite of a precedent, because the result that it describes isn't cancelling the effects out.  

[Bakunin]

Back in my Warhammer Fantasy days, there were a few units that could reroll failed attacks or wounds, and a few that forced successful attacks or wounds to be rerolled. When they faced each other, you ended up with the hilarious sight of rolling every die twice, since you had to reroll all hits and misses and no roll could be rerolled more than once. In practice, a lot of players I knew just rolled once since it didn't matter.

For sanity's sake, I'd just say any completely opposite effects just don't do anything.