Removal of the restrainer.
I imagine this is a big reason why God says flee to the wilderness. It will be so much harder to resist sinning without the Holy Spirit. We are all weak, David and Sampson as strong as they were failed, so would I. If I can fail with the restrainer I can only imagine how hard it would be without.
The price for not choosing to turn to God might be an earthly death, but following the deception and taking the mark will mean unimaginable eternal suffering.

The anti-Christ will survive a seemingly unsurvivable wound. 
I wonder if during the rapture chaos this wound takes place and he appears days after proclaiming to be the savior with calming words to deceive many. The words will be convincing to those already deceived. I fear it will be related to an existing false church, giving a false hope. Marking his followers as a special group promising a skewed Biblical deception.