[1] I wish be be able to purify Witches into another stage in the Puella Magi life cycle. Drown in Sorceresses and die!
[2] I wish that instead of becoming Witches, Puella Magi simply become normal humans when their magic runs out!
[3] I wish that Witches could harmlessly eat/feed on grief by forming contracts of mutual benefaction with either humans with high enough potential or Magical Girls!
OKAY
1 Will allow for Witches to be purified, adverting Sayaka's tragic ending ala canon and maybe even Madoka's when she turns into Gretchen. It means that Witching isn't game over for a person, and that we might even produce even more energy to stop Entropy. It's a tentative win for everyone.
2 Is a huge fuck you to Incubators, and solves much of canon. No more Witches can be made from this point on, and since Wishes follow both letter and spirit I can imagine that those normal humans will not come out dead or wrong. Homu is happy, Sayaka becomes alive again so no more 'IM DEAAAAAD'. If QBies can still harvest the energy then it's another tentative win.
3 However is a huge change in the Puella system, as Witches are now capable of becoming good for humans. My thought on that was instead of kisses making people kill themselves, they harvest grief from people. This would be super helpful for Puella and mentally unstable people. This also means we can have moments like in Rebellion with cute Charlotte being cute.
Note: Just throwing this out there, Firn stated that we can wish we held dominion over Cthulhu in Rolz, and that we would get a bonus power that would allow us to make extra cthulhus. Imagine how awesome it would be to go to war with the incubators with an army of Great Old Ones.
I don't care for crazy awesome when compared to feels and providing happiness.