I have been playing this character pretty much exclusively since he dropped, and I totally love him. He has really short range and awkward/clunky movement, but is rewarded with absolutely massive damage output on a successful read. I don't think the character needs many tweaks, but I think there are still a handful of places to improve:

1. He needs a Hustle. Point blank, the fact he doesn't have one is silly. You're telling me DIO can't taunt his opponents? Aside from being out of character, it really feels like a piece of his kit just missing for no reason - since Deo is so meter hungry and so vulnerable to getting zoned/camped with his awkward movement and neutral options, not having a Hustle to build some meter and force his opponent to approach (oh ho ho) closer into his preferred range feels like a missed opportunity. If there's only one change the character NEEDS, it's this one.

2. Similarly to above, he should probably have some kind of Dodge/Roll/etc. The moment you get put in disadvantage, you start to have a really, really bad time with no way to move and escape pressure. Sometimes you can make do with a flipped Uppercut / Silencer / Roundabout / Stand Crash, but again, his lack of mobility is just a massive killer here. That, or some kind of Stand Dash super dash. Still make it slower than the standard, but some method of actually beginning the process of closing the gap instead of just trying to awkwardly jump -> Silencer for momentum or something.

3. I like that Deo is mostly a ground based fighter, and I'm fine with his movement being restricted, but I think the fast teleport dash just has too little range to be worth using for how slow it is. It can be used for weaving through telegraphed projectiles, but that's about it. I don't think it needs much, but a slight range increase would be nice here.

4. Blood Blades. Again, I really like these for the most part. They're your only projectile, so you use them a lot to cover space as you approach, and for how slow they are, I think it's fine that they're unparriable, especially since you can hit them to get rid of them. My only change here would be a toggle on them so that if you're in the air, you can still throw them at an upwards trajectory. As is, it feels like his most important space covering tool just becomes useless the moment they're above you. I don't think full 360 control is even necessary here - just make it an up/down toggle and leave it at that.
(Side note: the global patch that gave him the ability to Super Fall is so wonderfully useful, I'm amazed it wasn't there already. Definitely a tool that Deo appreciates having quite a bit.)

5. This one is the most iffy suggestion and probably isn't necessary if some of the other tweaks go through, but I think he should probably have at least one move with armor on it, as his frame data isn't quite privileged enough to fully slug in the range he wants to be at. A move with some armor to help him with RPS would be nice, maybe make it stand off akin to Diavolo's? As it is, once I have my stand out I almost never want to desummon it, since Hook Punch and Stand Crash are such vital pieces of his neutral game. His stand off has better supers, but considering you want to hoard meter for time stop (and need to have stand out for it), a little bit more incentive to fight with stand off than just Scales would be appreciated.

Overall, I absolutely love the character, and I want to be clear that I don't want to in any way remove his weaknesses - but they feel just a touch too crippling at some points. The payout is absolutely there, his damage is huge and crunchy, but actually getting into range to apply your pressure is just a touch TOO difficult. Just one more move to make him a little less predictable would work wonders. I definitely think ALL of these suggestions would be too much (although would still be a huge show of restraint compared to a lot of other modded characters, I like how this one has very clear weaknesses to exploit), but just a handful of tweaks can make this character really sing. Or wryyyyyyyy, as the case may be (hell make Wryyyyy the sound effect for the hustle in stand off - you can have that one for free lol).

Oh, and a tip for aspiring Deo mains trying to get the fat, juicy damage: Roundabout is an EXCELLENT juggle tool when close to the ground and is really hard to DI effectively, letting you loop groundbounces and use Silencer / Hook Punch / etc to carry people to the corner for nasty wallbounce loops. But the REAL sauce is when you learn how to properly use Time Stop to reset proration and lock your opponent out of burst - if you can tell two more hits will build the opponent their Burst, you want to use the first hit to get yourself to +23/24f advantage, and then pop Time Stop. Time Stop takes 25f to start, so that extra frame or two of being actionable will NEVER let them escape, but they are TECHNICALLY actionable, which means the Time Stop combo will have totally fresh proration and scaling. Combine that with Road Roller doing an OBSCENE amount of damage as a combo finisher, this is how you get scenarios of "bait burst -> deal 5k -> time stop -> deal 6k" to just execute people burst safe from 2/3rds life. Deo can and WILL kill you off the right mistake, similar to Marisa in SF6. Make them respect you.