I had an interesting thing come up in a game yesterday. I was playing Wraith and the villain was Iron Legacy. I had Combat Stance in play and Iron Legacy had Demoralizing Presence. If Demoralizing Presence forces Wraith to deal damage to herself, does Combat Stance now make Wraith Deal damage to herself?
Yes. Same with Ra's Flame Barrier.
We lost Wraith to an incapacitated Fright Train exactly that way in our Freedom Five vs. Vengeful Five game yesterday.
That's...weird...
We have a houserule that targets that have some sort of retaliation won't hit themselves with it. Gauntlets of Perdition will still activate, but Backlash Field, Flame Barrier, Combat Stance, the Chairman, etc. don't.
Not strictly official, but it makes a lot more sense than Wraith punching herself in the gut every round because she's got the Sewer Flu.
Looking at some of the known symptoms of Sewer Flu, which include punching yourself already (see Afflicted Frenzy), I can easily believe she'd start punching herself.
You can come up with thematic explanations for it. Combat Stance is about Wraith having trained herself to be extraordinarily alert---but when she's infected, she's weakened, so maybe staying that vigilant actually puts an extra strain on her body.
For Flame Barrier, maybe when Ra's infected he starts having trouble controlling the fire around him. He's keeping that barrier up all the time, but when the infection kicks in he gets dizzy, loses his focus, and burns himself.
You've gotta go a little bit afield from what the effects are normally signifying, but I think you can still keep things interesting and flavorful.