[Byleth realised that only when there was no impact from his strike - it was a spectre haunting the Communion, not some sudden, tangible threat taking advantage of their distraction. Set's fear had spurred him unthinkingly, but Byleth didn't feel embarrassed or sheepish for his reaction. He felt a little frustrated that he didn't have the power to dispel threats of the imaginative kind, and just levelled a harsh glare where the spectre had been before refocusing on Set with a considerably gentler expression.]

...I'm sorry.

[Byleth lowered his arm, the only sign of his failed attack being the thin layer of ash clinging to his gloves - ash that immediately stained Set's forearm when Byleth abruptly grasped it: gently, more at an attempt at reassurance, his hand as warm as the sand beneath the desert's stone and leaving streaks of dull grey.]

We may not be rid of him, but I'm sure we can drown him out. I can sing to you, if you'd like, or perhaps I can show you a battle from one of my memories? He may not be able to haunt us there...