Okay, so. Here's why I think this idea is cool, and why I think it is a great mechanic idea.
Currently right now the problem with aerials is that their power and usefulness is largely dependent on the amount of landing lag they retain when you land. This is to such a degree that aerials like Ike's forward air, despite having incredible power and properties (huge hit box, disjointed, offensive and defensive properties, good damage, KO's) is relegated to being a downside to the character as opposed to an asset simply because landing with it makes you vulnerable. What this means is that if you can't L-Cancel your aerials, your aerials don't autocancel, and if they don't have naturally low base landing lag, they're not reliable tools to use for your air-to-ground or ground-to-air game, and you as a player are punished or discouraged from them. To me this is a big problem because one of Smashes biggest hallmarks compared to other fighters is the autonomy and control you have in the air, and I don't think things should discourage you from using aerial play, tools, or maneuvers.
Now, to clarify to anyone who didn't understand this suggestion properly, I'm going to use Ike again as an example, specifically with his down air.
Ike's dair has a base landing lag of 29 frames, or roughly 1/2 a second. This is forever in fighting game time. We'll call this landing lag the "base" lag. Ike's down air also has an animation duration of 55 frames, but we'll say 1 full second or 60 frames for simplicity. Ike's hitbox comes out on frame 16-30 with the strong hit box that spikes presumably on the 16th frame, so kinda on roughly about 1/3 of the way through the full duration. I know he has auto cancel frames, but let's ignore this for now and pretend he doesn't.
Ideally in a scenario where you could L-Cancel Ike's dair, you would want to do it shortly after frame 16 from a short hop to maximize your safety as well as your ability to react quickly because the hitbox would remain out just prior to you landing. Unfortunately, without L-Cancelling, the base lag is too high to warrant doing this. L-Cancelling reduces the landing lag by half, so that would be about 15 frames.
What this suggestion suggests to do is that if you were to use Ike's down air and land on frame 1, you would incur a large amount of landing lag, while if you landing on frame 55, you would incur very little to no landing lag. What I believe an interesting proposition would be is to have the the amount of frames that have already passed act as the amount of frames that are reduced from the aerials landing lag based on a percentage, and up to a cap. So for instance, if Ike's dair lasts 60 frames and you land on frame 30, that's half the duration. So for the landing lag, which is 30 frames, we reduce half of that landing lag from the total, which would be 15. If Ike lands on frame 45, that would be a 75% reduction in landing lag, which would give the move 8 frames of landing lag. To avoid aerials being virtually lagless from being used too high up or for too long in the air prior to landing but still landing during their animation, you could use a % threshold, like 75%, to ensure that Ike's down air could only ever be 8 frames short.
What this does is it gives Ike an interesting way to utilize his dair in a multitude of ways. For instance, let's say you're in melee range of your opponent, and you're in your shield. You plan to use an out of shield dair because you predict your opponent is going to spot dodge in fear of you going on the offensive so close to him, and you want to push him with an out of shield aerial. With the way Ike's dair currently works, you would need to hit the strong part of the dair to even remotely justify using this as an option, not just because of how unsafe it is, but because the follow up isn't there thanks to you incurring nearly half a second of lag no matter how you use it or when you use it in the air. With this change in mechanics though, you could opt to go for a soft or early dair, to ensure you land on the ground later while you stay in the air suspended with the weak hit box. This will punish the spot dodge while also ensuring that if you manage to hit him, you have a follow up after because the landing lag will be much shorter. However, because Ike's dair comes out on frame 16, if you account for the extra air time you have until you land while hitting with the strong hit box, you might land on say, frame 20. That would be 33% or 1/3 reduction in landing lag, which would be only 20 frames. Given how much hit stun Ike's dair has, if you were to opt to do that, you could potentially still have a combo or kill set up. Neither is better or worse than the other overall, it just depends on what your needs are and what you decide to do in this specific situation.
This has a ton of application because there are a lot of aerials with unique properties and kinds of uses. You have things like Pikachu's dair with a hit box in the air while also having a hit box when they land. You have dive kick aerials. You have aerials with multihit hitboxes. You have extremely fast aerials. You have aerials that act like semi-spikes like Pikachu's tail flip or Ganondorfs uair, or combo starters like Marios Uair. You have pop up spikes like Falcos dair. There's a huge array of possibilities here.
What this change essentially allows for is it allows for a use for the slower aerials that still have interesting attributes and uses, but without having them be equivalent or better than the aerials that comprise of little landing lag that might be your bread and butter.
Certain aerials like say, Ike's back air, should have little landing lag regardless because it's simply a bread and butter move. And for all intents and purposes, this change would mean very little to Ike's back air. But what this could do for his dair, his up air, and his fair is incredible. Some characters might not care at all, like Meta Knight, who naturally have low lag on all their aerials. But other characters would benefit tremendously from this while still being the slower characters iconic to their theme and design.
What's also wonderful about this is that it is intuitive. It makes sense to the player to understand that if they take longer in the air with the attack, it will be less time on the ground when they land, and vice versa. While there's a math behind it, you wouldn't necessarily need to know the math to apply it.
