Alright so 1st thing is 1st.
Max out legionnaire to 3. Both Dux and legion should always be 3, because its the 2 best dragunity that a basis for most of your plays such as Legion + Akly to pop 1 face-up monster and 1 face-down trap. It acts as a stunner to get rid of annoyances such as Thunder King and possible good face-down hits.
If you are gonna use Atum in your Dragunity the staples should be...
3 Dragunity Dux
3 Dragunity Legionnaire
3 Dragunity Mysletainn
3 Dragunity Phalanx
2 Dragunity Aklys
1 Red Eyes Darkness Metal Dragon
Thats 15 monsters already. ( I use card trooper in real life in my dragunity. Its good to cover over Thunder King and boss monsters. Although I haven't tested online yet I top locals with Trooper in them Adding in Tour Guide is also good, because you need it, if you don't have any dragunity plays to go off from you can rank 3 into something to start off like Zenmaines or standoff simple monster like Thunder King).
You add in Zephyros (which u should only run 1 of), it adds to more combos to your list such as : Summon phalanx, tribute for msyletainn, return mysl for Zephy and synch 6. You only run 1, because its pretty much useless after you use its effect (which can only be used once per duel).
You need to have 3 msts. The deck relies so much on getting that normal summon in and being able to use effects. When you are in a duel your opponent will know this and try to stop them. You are gonna need your summon and effect to go through.
Max mysle to 3 for more atum plays rather than just dux all the time. Max terra to 3, and cards of consanance to 3 it makes the deck a whole lot faster and ravine is necessary to maintain the speed of dragunity.
-1 Foolish burial with cards of consonance it maintains a +0 instead of -1. Foolish isnt needed, because in theory u have about 6 cards that can allow you to ditch those lv 2 tuners.
I would add in call of the haunted 2-3 to add in more plays if your lv 8 synchros are getting destroyed, or to reborn some of your lv 6 snyhchros for more options to rank 6 more often.
Cards I would take out: The torrential, the mirror force. the prisons and the fiendish chains.
You need dark hole in there, which you are missing. Icarus attack should also be added. Icarus is a chainable that pops cards as well. You can find space to fit both lance and icarus. Mind control is good for XYZ and Synchro plays you can do, if your play wasnt succesful do to a effect veiler, or there is tkr in the way.
Extra Deck Wise: Tested Librarian, and the options of you ever needing to summon it is low. The only synch 5 combo is Leggion + Phalanx and Catastor will be a better option as usual.
You don't need 2 stardust dragons. That would be if you are running Stardust Dragon Assault mode. The chances of needing 2 stardust are really low. If you gonna run 2 stardust do so only if you run starlight road.
Add in a rank 4 such as utopia or maestroke for added defense. Case might happen where u have 2 level 4s and nothing to go into.
Sword Breaker is better replaced with Messier 7. Messier 7 can return the monster, usually gonna be an XYZ or Synchro monster thats in the way, and allows you to re-use dragunity monsters thats already used up. (If pot of avarice hasn't been aplicable yet).
Black-winged dragon you don't need at all. If you are worried about burn, you should side it. Thought Ruler would be a good replacement for it, because its a good lv 8 standoffs monster that gets over cards like Fiendish Chain, Prison etc.
Siding wise:
2 Veilers and 2 Maxx should be in there.
I side in 2 soul takers to take out cards that negate special summoning to get over cards like Kristya, Thunder Kings, and boss monsters that dragunity alone have trouble getting over such as Dollka and Laggia. Its effective against heros as well.
I have 2 of each of the light and dark mirros, along with 2 soul drain basic siding.
Royal Decree is good in side, I would side in Dust Tornado rather than twister, because of the new addition of Fire Fists in the meta. Thunder King Rai-Oh is unsafe to side, because it hurst your deck a lot. You need to be able to search your cards out each turn to make sure u have a 1 card play each turn.
Well I kinda went all over the place. Sorry its not as organized, but I hope I helped. Glad I run dragunity irl xD with no phalanx (more of a stun like dragunity said from Satella himself but meh).