Sometimes, when I perform an aerial combo, the enemy gets delimbed in the air, and I think that I want to go to the ground for the juicy OT finish instead of killing him in the air (super risky, and doing aerial combos is already risky on his own). So, all of a sudden I had an epiphany: what about being able to perform OT's IN THE AIR??? That would be fucking amazing, and would also be useful.
Of course, there would be some factors to take into account for a similar design choice. First of all, an aerial OT could be useful if it would also grant Ryu safe frames when he lands. So, in games like NG1 or NG2 versions it would be really great, because performing aerial combos on Master Ninja is quite unsafe, since some enemies will punish you as you touch the ground and you cannot do anything about that (you only wanna do them if there are no enemies around but it's still very risky, you are just going for style and you could regret about that). Though, it could also screw the balance and become a better version of izuna drop, while some players already ban that move from their gameplay to make things more interesting. I myself play Sigma 2 with no izuna drops since it's the most boring move in the game, and I like that the game keeps me on the grounds in many instances, I think it's a more elegant gameplay design. So, I don't know if I would prefere a game with aerial OT's or simply better ground options.
The game with better ground options would be Razor's Edge. Most RE gameplay is ground based and it's one of the reasons I like it. Though, there are instances in which enemies can be launched and delimbed in the air, so I think that game could be use some aerial OT's. Launching got well balanced in RE imo so aerial OT wouldn't be overpowered. So, you launch the enemy, if you delimb him inthe process you can go for the OT, maybe extra meter gain and safe landing frames, if he doesn't delimb you can choose to go for the izuna and use the rebound for setting up another one.
So, since RE can't be changed this could be a nice novelty in NG4. Though NG4 will never be released so this is just nonsense chat.
Edit: I forgot to mention, though, that even if I think aerial OT's would look really cool, I would probably prefere if NG4 had the least aerial game possible, unless they can make it interesting in some ways.