Does Roy appreciate +atk -spd, or neutral IVs?

I think I would go with the +ATK/-SPD version. I don't think his Spd matters much when he has his refinement. The only matchups where I think his speed is important would be against dragons, most of whom tend to be in that low 30's range depending on how they're built, but I think Warding Breath evens that out well.

Not sure what you plan on using for his B-slot but I run Swordbreaker on my Roy and I find it really helpful in avoiding doubles from the super fast sword units. Really helpful especially with a speed bane

Yeah, speed isn't really that important on Roy considering his refinement gives him Quick Riposte.

If going aether. He wants to be doubled so -spd is better. Plus he has lavg atk so the extra atk will indeed help him.

If going ignis/glacies. He doesnt wasnt or need to be doubled so neutral is better. Plus the dmg from the special will be be more than enough to finish off enemies

If going aether. He wants to be doubled so -spd is better.

If going ignis/glacies. He doesnt wasnt or need to be doubled so neutral is better. Plus the dmg from the special will be be more than enough to finish off enemies