I don't know too much about this character, so if you disagree or want to add, please post, and I'll edit it in!
Normals
5A
Roa smacks you with the back of his forearm. It's a decent whiff cancel but not the greatest, but since he has 5C and 6C with great range, you can do great fakes with it. Combo fodder in some of his harder combos. This hits crouchers.
5B
A downwards smack with his hand. Mostly combo filler, nothing really special.
5C
The one and only double kick. Extremely powerful attack. Fantastic range, works as an anti-air, great off of whiff cancel fakes, good damage in combos, there isn't much this move doesn't have.
2A
A short swipe with his hand. Combo filler/hitconfirm material. Hits mid.
2B
An odd little kick. Hits low. More combo filler.
2C
A sliding kick that knocks down, hit low. Good for launching in combos, and has good range, can be used as a throw tech punish.
6C
A long ranged smack with his hand. This has incredibly good range, almost as good as the second hit of 5C. Useful in combos as a launcher off of 2C and as a way to combo into 236C or 22C.
j.A
A long ranged hand smack around chest level. Works in air to air a bit, but it's not great.
j.B
A weird little kick with not too much range. Looks like it might crossover like H/F-V.Sion j.B, but it doesn't.
j.C
A long ranged kick. This is a good move, and useful in aircombos, as if you're good, you can do j.C ad.C dj.BC for an airstring.
Throw
Roa grabs the enemy and tosses them, they are able to tech. The tech is punishable easily if they neutral or forwards tech, but back tech is harder. Throw into the corner is very safe for you, make them respect it for OTG.
Air Throw
Roa throws the enemy down after charging them with lightning. Does decent damage but resets to neutral, not one of the better throws. Does knock down though.
Specials
236ABC
236A
A decent lightning strike. Chargable. Comes out quick and has good range, and charging it increases range. +frames on block if it is charged. Works well at a decent range to catch jumpers. Also, it's EX cancellable. This move also cancels into 214A/B/C or 22A/B/C. Charged cancels into 623A/B/C as well, and 236[A] 623C does not have the ex cancel penalty.
236B
A similar lightning strike. Also chargable. Not quite so quick, and it hits twice. +frames on block if charged. This also cancels into 214A/B/C or 22A/B/C
236C
Three lightning strikes in front of him. Wallslams, extremely useful in his corner combos. Huge damage opportunities off of this. Takes 100% meter. Enormous range, will punish Nero setting off the zoo, F-W.Len planting ice, and random zoning tricks. Extremely dangerous for the opponent.
623ABC
All of these can be done in the air.
623A
A two hit anti-air move. Moves diagonally up.
623B
A four hit anti-air move. Moves in the same manner.
623C
A seven hit anti-air move that wallslams. Takes 100% meter.
214ABC
These can be done in the air.
Each of these moves just plants an orb at a different location on the ground, A being the closest, and C being the farthest. Doing this move in the air will have the orb be horizontal in front of him, no matter what button is used. Executing the command again with the same button will shoot lightning from the orb, and you can combo from this. The air version is extraordinarily useful and will disappear when you are hit.
Planting the orb cancels into 22A/B/C.
22ABC
22A
Charges lightning meter one at a time, can be held to charge more. This is the useful version, don't use 22B.
22B
Charges the lightning meter 3 at a time, not holdable. Don't use it, it ruins the lightning's properties.
22C
Releases the stored lightning in a bolt in front of Roa. Different charge amounts do different things. Anything charged above 4 with 22A will launch them into the air untechably. Six, and only six, will circuit break. Anything above 4 floats them, but not if charged with 22B. DO NOT USE 22B.
If you have paid attention, you will notice that you can do a cancel chain of 236A 214A 22A or the like. This can come in handy, keep it in mind. 214A 22A is more useful, though.
Arc Drive
Roa strikes with a lightning bolt similar to 236A/B, and if it hits, the enemy is gradually pulled into a large cross, where they are hit by a lightning bolt. Large damage, combos off of 6C. Useful, not really punishable on block.
Last Arc
Some long boring animation, then it does damage. Ground shield, don't try for this in a serious match unless you are the god of shielding, but you probably aren't.
Combos
Meterless:
2A 5B 2B 5C (2) 2C 6C j.BC dj.BC airthrow.
This is a pain to hit on some characters, you can try adding a 5A before 6C.
2A 5B 2B 5C (1) 6C 2C 214A 22A
Knocks them down, gives you one lightning meter, and adds an orb on them. You also get a meaty off of this! Abuse this if you want oki.
Alternatively, tiger knee an air orb.
5B 2B 6C 5C (2) 2C also works.
Meter in the corner:
2A 5B 2B 5C (2) 6C 236C 2C 6C j.BC dj.BC throw
This only works on Aoko, Tohno, Nanaya, Kouma, Miyako, Riesbyfe, Wara, Len, W.Len, Ryougi, Nero, and Kohaku. Remember those!
For other characters (Sion, V.Sion, Roa, Ciel, Akiha, Arc, Warc, V.Akiha, M.Hisui, Sacchin, and Hisui), use this:
2A 5B 2B 5C (2) 6C 236C 6C j.BC dj.BC throw
If you're in max and really need that extra 500 damage, you can also do this on character that 2C will hit on
2A 5B 2B 5C (2) 6C 236C 2C delay 236C 6C j.BC dj.BC throw.
5.5k on Riesbyfe, which is respectable damage, but at the cost of 200 meter, it's rarely useful.
Lightning Combos (22C)
This is why you charge up to 4.
This works anywhere.
2AB 5B 5C (1) 2C 5AA 6C 22C 214B 2C 5C (1) sj8.BC sdj.BC airthrow.
Probably in the corner:
5B 2B 6C 2C 5C (2) 22C 2C 6C j.BC dj.BC airthrow.
This is in the corner, with meter
On Sion, V.Sion, Roa, Ciel, Akiha, Arc, Warc, V.Akiha, M.Hisui, Sacchin, and Hisui:
2A 5B 2B 5C (2) 6C 236C 6C 22C 2C 6C j.BC dj.BC airthrow
On Aoko, Tohno, Nanaya, Kouma, Miyako, Riesbyfe, Wara, Len, W.Len, Ryougi, Nero, and Kohaku:
2A 5B 2B 5C (2) 6C 236C 2C 6C 22C 2C 6C j.BC dj.BC airthrow.
Any combo can be cut short at 2C to do the 214A 22A or j.214A setup.
Strategy
This character has good range and a good ground throw. Abuse these along with his powerful zoning with orbs to keep the opponent where you want them. His 5C is legendary good, and whiff cancel fakes can be chained, for example, 2C 5A 5C 2A 6C is a viable double frametrap. He hits hard in the corner with meter, but his damage is low without it, so try to keep his lightning bar up. His lightning bar charge can be used almost as a whiff cancel, though it's very obvious so try not to do that too often.
Your goal is to have a low j.214A orb in front of you. Always. If you have this in front of you, along with other orbs all over the place, getting in on you is extremely difficult. This character has the ability to switch between offensive and defensive very quick with careful orb placement, so try to keep your opponent on their toes. Be careful if their character can out-turtle yours, of course, but remember, your 236C is very long range, so if somebody is trying to out-turtle you, if they're not blocking, they should be getting hit by 236C. I'd recommend saving meter on Aoko and Nero and scaring them out of doing anything with 236C.