General Strategy
Summary
Shadow Dio's moves work well for a rushdown heavy playstyle, and that's what you should be focusing on mostly. Your plan is simple: open up your opponent and deal massive damage with simple combos. He can easily switch between low and high attacks during his rushdown attempts and his Stand attacks can be used as a short-range projectile, either to punish moves, set up a safer approach or just poke and chip at the opponent's health or stand gauge. Still, it's a tool to not be abused as a spammy Shadow Dio is very easy to punish, especially when you mistime your attack. Lack of any wake-up tools also adds bonus risk as a simple knockdown may prove fatal.
Remember that you also have a few projectile attacks to help you during the game: although slow, knives can be used for chip damage, long-range punish and combo starters, while the laser is just great for long-range projectile wars. The unblockable version of the laser can become one of your best late anti-airs if timed right and generally free damage. The long startup time of your projectile attacks and laser's recovery time can mess you up though, therefore you should only use them when the opponent least expects them, or from fullscreen against chars that don't have any long-range attacks to counter with.
Shadow Dio has a variety of very good airborne attacks which are capable of beating most characters in the air, plus he can combo with 5S afterwards if they were hit midair. Using j.5S to hit opponents while jumping behind them is is a risky strategy as it leads to high damage, but can be avoided for a damaging punish. One of many strengths of Shadow Dio is his ability to quickly perform Stand Crash combos and his strong oki game. Two or three well-placed combos can end the round. Do not abuse his Super attacks as they can be easily punished, while others are very situational or useless. Save your meter for the Time Stop and use 236AA super only in case of danger. Charisma can be used as a powerful reset tool if done right or at the very least deal bonus high damage.
You can attempt to play defensively as Shadow Dio is good at poking thanks to his fast dash attacks and 5S/j.5S, however, he's susceptible to quick dashes as he cannot punish them while his Stand is out. Always remember to mix your strategy to be unpredictable.
Okizeme/Resets
Shadow Dio has a lot of moves that cause hard knockdown, like his regular and command grab, 3C and 2S. This gives him many ways to go into his okizeme, where he has a variety of options with different rewards.
- Fake crossup: Though commonly known by this name, the specifics are slightly more complex. This is the one you will use the most as it works on most of the cast when you score a knockdown with a grab. If you short hop over the opponent while they're on the ground you have three options: j.5S for a fake crossup, empty hop 5C/2A for a real crossup or empty hop grab for another go at the mix. What makes this powerful is that hitting the first two options will reward you with a full loop into more okizeme. Against characters with longer wake up speeds you may not want to short hop immediately and instead walk back for a bit then do a full hop: this allows you to hit characters like New Kakyoin who tend to throw off your timing.
- TW21 50/50: A well placed, meaty 41236S next to the opponent sets up a pure high low 50/50 against most characters (their crouching hurtbox has to be tall enough). Follow up with either an immediate 9A for an instant overhead or 2A for a low. Let the stand continue the combo and use 3C after it ends to get a knockdown and set up more oki. Keep in mind that if the opponent's wakeup is too fast you won't be able to meaty them with another Stand move, because 41236S takes a while to disappear.
- Tick throw: You can take advantage of Shadow Dio's great grab to introduce more mixup options into your okizeme. Some good normals for this purpose are 2A, late d.2A and delayed j.A.
