So my opponent attacks. I use criminal past to have this attack "be considered block during its block step"

Then i use Blind Loyalty to make this attack unblockable.

Attack blocked? Damage to the face?

You make the call.

If the attack is made unblockable, then you skip the block step all together. Therefore, the Criminal Past E will have been for nothing because you will still take the damage of the attack (barring any other effects of course).

*STAMP*

unblockable = block step skipped.