My guess: Ashley/Ella. Anastasia was very much hinted to be Ella’s stepsister (though it was never outright stated), and the fact that we had an Ashley cameo in the first ep of Wonderland only strengthens that guess.
Maybe he needs Ashley’s help to get back to/save Anastasia?
Could also be fun for Ashley, with her new baby (who should be about a year old now) to offer some advice to MM…whom she was already friends with back in the EF when they got married.
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing