I dont think any of the sword users bar new Ike have any "unique" advanced tech int he same vein as say fox//falco//wolf with wave shining. They tend to reward good spacing, zoning, and having a game plan for each match up rather than "I'm going to run at you and hit every button on my controller so quickly Einstein's theory of relativity will be brought into question" tech skill.
I think most of you mileage in roy (and by extension marth) is going to come from understanding your fundementals, match ups, hitboxes, general movement (things like "how far can i chase off stage with nB and still be able to not die"), etc etc intuitively. For example, I've found roy really suffers in match ups where the opponent has no incentive to go in on roy's baits like samus (why try to contest sword o' seals when you can leleleleleel super missles?).
to add onto @
Azureflames
list, ftilt is amazing in match ups against other disjoint-centric characters as a spacing tool.
I'm fairly certain (and you can check the hitbox thread to prove me wrong//right) that Downsmash on roy is his fastest startup on a kill move, which makes it almost as good crouch-canceld as fox//falco's (****tier angle tho)
its not really unique, but wavebouncing/b reversing DED as a mix up in approach is sometghing i've begun to do.