Powers of Two Trophy

This is easiest if left until you've acquired ALL the characters. (At the beginning of Act 3, you'll have all the basic characters unlocked, provided you've been successful at hunting, you'll probably have the three Item Unlock characters as well. Jean Grey, Hulk, Thor). Once you've got them all, head to the Simulator Challenge 'Basic Combat' and clear it up to the infinite spawn switches. Once you get there:

1. Choose a team of 4, but focus on the first character in the line up.
2. Perform a Fusion with each of the other 3 characters.
3. Swap out the 3 secondary characters with 3 new ones.
4. Repeat step 2.
5. Continue this pattern until you've finished with character 1.
6. Swap character 1 and repeat the process.

NOTE: A fusion counts for both characters, regardless of who initiates. So if I use Jean Grey and Fusion with Hulk, I DO NOT need to use Hulk and Fusion with Jean Grey.