- Hellfire Club's Inner Circle
- U-Men (Appears only as illusion)
- Riko Nirasaki
- Koichi Kaga (Mentioned)
- Unnamed Flying Mutant Boy (Appears only in flashback)
- Phoenix (Jean Grey)/Dark Phoenix (Appears only as illusion)
Emma has found out Mastermind has been sneaking around to find out where the source of the mutants is coming from. Before Mastermind can put her into a trance, Emma turns to diamond and begins fighting him off. The X-men arrive in the middle of their fight; because Emma is the only one to see through the illusion, they think she's attacking Jun. Mastermind quickly puts Wolverine under his control, making him think the X-Men are the U-Men. Marsh attacks Hisako and Emma, while Cyclops and Storm manage to badly wound Wolverine to the point of him falling unconscious.
Dr. Sasaki and Beast arrive next. Mastermind runs towards the doors hiding the secret, but is guarded by Marsh. Cyclops hits Marsh with a blast, which is directed to destroy the doors. Emma turns back to normal, disabling Mastermind's psionic field. Now everyone sees him for who he is. Wolverine wakes up, finding Mastermind, Marsh and Rat are there. He decides the party is just starting.
- Original airdate: June 3, 2011
- English airdate: December 16, 2011
- In the English version, Mastermind explains that Emma already possessed the ability to turn into diamond before the U-Men abducted her.
- He simply made her forget she had the ability back when she joined the Inner Circle, as he needed to be able to manipulate her for his own ends.