Jesse La Flair performs stunts for movies and so it wouldn't be crazy to enlist his services for the Assassin's Creed series, considering it's one big parkour theme park.
The athlete left a comment on one of his YouTube videos that was discovered by a. Running up walls is fine, but it's time to stop this horizontal discrimination.
"What if I told you I may or may not have worked on the NEXT AC and they may or may not have added the ability to Horizontal Wall Run in the game..." La Flair on his Parkour Tutorial video. Curiously he titled it 'Assassins Creed: Horizontal Wall Run - Parkour Tutorial', except that no horizontal wall running yet exists in the series.
Ubisoft's Prince of Persia series has had horizontal strolls along walls since sand was invented, but Assassin's Creed for whatever reason favoured all other kinds of building traversal over this particular ability, which really would have helped in numerous scenarios like wall-running air-assassinations.
Assassin's Creed: Unityfor PC, Xbox One and PS4 by Ubisoft.