Byleth's D-Smash is the most damaging smash attack in the game, dealing about 40% when fully charged. Along with this, it has bonus shield damage, meaning it is a strong shieldbreak tool. Fully charged, it will almost always break shield, and uncharged it will break shield when combined with another hit from most of Byleth's moves.
This move hits once on each side, and both swings are equal power. This can be good for a read on a roll, as it can also catch other options. It can also be used to callout a spotdodge.
It cannot be comboed into or out of aside from a jab lock.