Re: Avengers 2 and X-Men DoFP are both using Quicksilver and Scarlet Witch
They're not equal parts X-Men and Avengers material. They're 90% Avengers. In Wanda's case 95%. Fox can use them because they're mutants.
2014 - Captain America: The Winter Soldier | The Amazing Spider-Man 2 | X-Men: Days of Future Past | Guardians of the Galaxy
2015 - The Avengers: Age of Ultron | The Fantastic Four | Ant-Man
2016 - Batman vs. Superman | X-Men: Apocalypse | The Amazing Spider-Man 3
TV - Arrow | The Flash | Gotham | Constantine | The Avenger | Hourman | iZOMBIE
TV - Agents of S.H.I.E.L.D. | Agent Carter | Daredevil | Luke Cage | Iron Fist | Jessica Jones | The Defenders