As the title suggests, I’d like to put forward the idea of adding a new title for reaching a high number of Honorable Kills, something like 250k, 500k, or whatever number the staff decides to choose.
In Cataclysm, Blizzard introduced a title and achievement at 250k Honorable Kills: The Bloodthirsty).
Considering how many players already have well over 100k HKs (the threshold for the of the Alliance / of the Horde titles), I think a lot of people would appreciate the addition of a new milestone title at a higher HK count.
There are also some unused titles in the game files like Assassin, Prophet (?), Archmage (?), etc. I’m sure the staff knows the full list better than I do, but it could be cool to assign one of these that fits to a new HK achievement. Especially since there are "new" titles for arenas like the Supreme, Plainsrunner, Warbringer, the WIT titles, etc, titles that were not present for certain milestones in OG Wrath.