User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-4254431-20140814134401

I figured it out!How Rogue and Unity are related


 * Speculation Spoilers**

I'm pretty Shay kills Arno's biological father.

Why? Arno's father is french and most likely operated during Seven Years War making him a 'brother' or Shay did it cause he was told(for story reason).

Also, maybe in Rogue you play as the Abstergo Employee from ACIV see the ending and the assassins contact a different person to relive Arno's memories to find out why Daddy Dorian was killed.

Proof: screen shot of young arno, interviews where Amancio says you play in Versailles at the beginning of the game,and ending of ACR connects to ACU.