Input

The input is so extremely simple that I worry I won't be able to explain it well. The only input is to fast-fall after using uair, or vice-versa. Sometimes, if you are already midair, then inputting fastfall and uair at the same type can work as well. That's it.

Fast-falling is only possible after hitting the apex, or peak, of your jump. Therefore, it's easier to pull off the dragdown if you don't input jump and uair at the same time. If you input both the commands at the same time the timing will be tighter, and you may find that you land the final hit of the uair before fast-falling.

💭Note: When playing online fastfalling after inputting jump, then uair is easier to pull off. That is, inputting uair with a tiny delay after jump makes it easier to fastfall before landing the final hit of uair. It may help to think of executing the inputs like going down an ordered list. When playing offline the timing of the controls are way more responsive and snappier, so the above-mentioned advice doesn't apply as much when offline. Essentially, it's way easier to pull off the dragdown motion offline than online.

Of course, the explanations so far only applies if you are attempting a short-hop or full-hop uair dragdown. The uair dragdown can be used in many situations, so once you get used to fast-falling the uair you can start to look for other areas where you can execute this tech.

1. Jump
2. uair
3. fastfall
...in that order in quick succession. The less time between steps 1 and 2 the less wiggle room your opponent will have to act.

In midair you have more flexibility with the order of inputs. You can either fastfall → uair on your way down, or uair → fastfall, or even uair and fastfall at the same time:
1. Start midair
2. fastfall → uair OR uair → fastfall OR uair + fastfall

Practice

Once you understand the inputs the next step is to practice it in Training Mode:

1. An easy way to practice the dragdown is to use Up-Throw to set up the dragdown. This setup is an effective string on its own as it can be looped over and over again, but the opponent will probably break out after 2-3 loops. Practice this over and over again until you feel comfortable doing it.
2. Likewise, dragdown upair can also be practiced via down-throw. Down-Throw can be followed up with a dragdown-upair for another down-throw, and this can be looped over and over again. This method almost always requires the opponent to have some damage prior to the combo. However, this setup is a bit harder to loop than up-throw, it being largely contingent on your opponent's percent, weight, and DI.
3. Next is the most important and difficult step; Practice your dragdown-upairs against real opponents. It's important to get used to it by playing against people who aren't just going to stand there and let you combo them. Make successfully pulling off the dragdowns your main goal when playing against other people, rather than trying to win the game. You want to get a lot of experience executing these strings.
4. Once you get comfortable using dragdown-upair with up-throw and down-throw, start implementing them in your normal games. They provide easy and effective ways of racking up damage. These strings aren't true,(otherwise they wouldn't be called strings) but many opponents still get caught in them, and even if they manage to air-dodge out you can still followup in other ways. Be wary of over-committing to these strings against certain characters, mainly the ones who have fast combo-breaker moves they can throw out in midair. Characters like Mario, Luigi, Yoshi, or anyone with a similar neutral-air as the ones listed.

Mastering the Dragdown-Upair provides so much utility. Using dragdown upair as a followup to up-throw and down-throw are arguably the most useful applications of upair as it provides a relatively easy way to quickly rack up damage at early percents. These moves may not seem all that impressive, but there are some matchups where you may not have many openings to inflict damage, and these strings can help you get much more value with each neutral win to hopefully close the gap.

Uses

The next step is using the dragdown upair as an immediate followup of a prior move. If you've practiced the dragdown as a followup to Down-Throw or Up-Throw those can then be looped for more damage.

1. Down-Throw → Dragdown-Upair Loop is a common option and deserves a more detailed explanation.
   
   If there is one big takeaway from Joker's dragdown-upair is that you can use it to loop multiple down-throws, and this string can provide as a potent option to rack up damage.
   
   In particular, most heavy characters in the game will be exceptionally susceptible to this string as their weight will make it difficult to break free in lower percents, which is when this string is viable. However, if the opponent DI's out correctly, they shouldn't get looped more than 2-3 times, but if the opponent does not DI correctly, they can get trapped in the loop all the way across the stage ending up with 50%+ damage. There are probably no other strings you can pull off as Joker that can inflict this much damage with such an easily executed string. It's by no means guaranteed, but you can potentially reap huge rewards just for doing a Down-throw and Dragdown-Upair over and over again it's worth attempting especially when playing against a heavyweight.
   
   When it comes to middleweight characters, this move's viablity is substantially reduced as they will be able to break out much easier. Therefore, multiple loops should not be expected. Against the lightweight characters this loop is even less viable, but can still work. It can still be used as a mixup, but it shouldn't be relied upon too heavily as you might just get off one Down-Throw and maybe nothing else.
   
   A compilation of some loops are shown below. These examples are probably closer to best-case scenarios.
   
   
🎬 Down-Throw → Upair-Dragdown Loop 🎬 🎬 Close 🎬

Note: There is a particular way of executing the upair dragdown that I consider to be the True way of doing it. Most of the loops that are in the compilation wouldn't fit this label. The true way is slightly tighter and gives the opponent less time to act making it more effective, but it can be difficult to pull off. Essentially, the true way involves inputting upair before you hit the peak of your jump, but even earlier. However, doing it like this especially in an online setting and still managing to dragdown before the final hit of upair is pretty difficult to do, at least for me. I still included an example for reference below.



🎬 True Down-Throw → Upair-Dragdown 🎬 🎬 Close 🎬

2. Up-Throw → Dragdown-Upair is another loop you can execute, but it's way more straightforward that I don't think it's worth getting into more detail over. Just know that you can do it multiple times just like Down-Throw, but not only is it easier to execute it also seems easier for the opponent to escape. The string can also be used to transition into another combo.
   
   
🎬 Up-Throw → Upair-Dragdown Example 🎬 🎬 Close 🎬

3. F-Air → Dragdown-Upair → Down/Up-Smash; This kill confirm requires its own separate guide.

To Be Added