Re: Synchronized Swordsman (PRC)
Perhaps when adjacent to one another, they get a bonus to AC, and possibly some other minor functionality or ability.
Another possibility is that they get flanking bonuses whenever they both threaten a target, regardless of whether they're actually positioned on either side.
Quote of the [insert timeframe here]: (Week? Perhaps! Year? Also maybe.)
"Those who have learned to walk on the threshold of the unknown worlds...may then with the fair white wings of Imagination hope to soar further into the unexplored amidst which we live."
-Augusta Ada Lovelace
(Kairos avatar by Elrond)