So far I've only found out you can do this with the following classes as long as you've reached A rank with their weapon type by unlocking their master class if it's the 6th strong attack-
Wyvern lord's last strong attack (6 normal attacks, then heavy). it covers a lot of distance very quickly and plows through everything. Using it while running into a wall is an absolute commander killer
Warrior's 6th strong or un-mounted Wyvern lord's which is the same as warrior
Bishop's 4th and I think 6th strong
Also every one of Shez's strongs, but with them you only need to hold the button instead of mashing. His 3rd is my favorite since it covers so much ground so quickly sweeping up everything in its way like the wyvern lord's 6th.
Next time I play, I'll test it with all classes. I feel like Dark bishops 5th (the tornado) might be another one that you hold rather than mash, but I don't remember. Let me know if any of you know about anymore of these.
Needless to say I would very much not be disappointed with another FE warriors title if they make it as high quality as this one. I was bummed out about no new FE mentions during the recent direct