Ms. Marvel was errata-d in Rules Reference 1.5 to say "return that event to your hand from your discard pile" instead of "return that event to your hand". This prevents the endless looping that was once possible with "Go for Champions!", which also received errata to remove itself from the game after being played.
The police won't come to your door if you continue to play these cards as printed, but for those who want to keep their games as official as possible, you should be aware of this change.
That was never possible to begin with. Part of the cost is to exhaust Ms. Marvel and deal 1 damage to her. Since each Champion character in play cannot take damage until the end of the round, and dealing 1 damage to her is part of the cost, you are unable to pay the cost. Therefore, you were never able to use her to loop Go for Champions!
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dcarriger
· 144
Once the distinction between "dealing" and "taking" damage was made, it was possible. Source: https://www.fantasyflightgames.com/en/news/2023/5/18/rules-reference-debrief-1/
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Stretch22
· 664