Here's a thought:
Has anyone ever played NeoQuest II and made it to the second half of Haunted Woods?
About halfway through that Act (Act 4) you meet the brain tree.
Remember what he says?
After talking to him a bit, you read this line:
Quote:The Brain Tree laughs. "Yes! Already I know what has happened, though I am immobile."
How could the brain tree suddenly be in Tyrannia in order to be in line?
The same goes for the Esophagor, I don't think he's allowed (or able) to leave Esophagor's swamp.
As for the rest of the sheilds, the next immobile Sheild character would be 39th month shield, which shows a mocking daffodile (sorry if that's not actually the name of the item).
Since the flotsam isn't in line, and the Brain Tree and Esophagor are stuck in Haunted Woods, then that would mean that a total of 3 are missing.
If you count up to the 38th shield other than the Brain Tree, Esophagor, and Flotsam, you will find youself at Fyora, the Faerie Queen: 3 years (36 months). Since the next immobile or excluded sheild would be the flower (month 39), it doesn't push back our counting anymore.
So could the answer be Fyora, because the Flotsam wasn't in line and the two great beasts of Haunted Woods can't get in line?