I found a bug(?) that allows you to add Iris winged version (from now on: "I.W.V") in your party without fighting her.
Step 1 - Actually beat her a second time (for the one that didn't do that yet) to allows you to add this version in your party.
Step 2 - Equip the MC skill (the one that allows you to relocate the girls in the map), while your are in your house .
Step 3 - Add normal Iris to your party.
Step 4 - Go to the "Central Square" (The rest area where you can normally find I.W.V.) and relocate normal Iris somewhere here, I suggest you to put her near the portal to be quick.
Step 5 - Go back to your house and after that go back to "Central Square". If all went well, you will find I.W.V. where you have relocated normal Iris.
Step 6 - Add Iris to your team. She should enter it in her winged version.
Step 7 - Enjoy I.W.V. as much as you want. You pervy son of a gun
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