Just need to repeat from earlier. My opinion is, a third difficulty should yield a Title, and NOTHING ELSE.

No cosmetics.
No minions.
No mounts.
No emotes.

Nothing except a Title. Why? Because if you put ANYTHING other than a title as a reward for that third difficulty, I can guarantee people will immediately start doing everything within their power to get it, EXCEPT run the raid at the difficulty. There will come to the forums in droves demanding a Gold Saucer variety just as nice, or perhaps better. Or a Mog Station version. Worst of all, they will start demanding that new difficulty be made easier so they can get what they want, and that wound ruin the point behind adding it in the first place. SE listens to those kinds of complaints.

Please. Stick to Titles, or nothing at all.