Not that Sephiroth wasn't naturally somewhat line-faced by default but there was a noticeable way his expression hardened as Gladio laid down the challenge; he heard it alright, even though he was looking up to where Xehanort had pointed at the time. He even seemed to narrow his eyes a little as he turned his attention back to those at ground level with him.

After a moment more of consideration he let out a huff of air through his nose as he picked the Slate out of his inside pocket to switch over to Illusionist; ready to cast Levitation no matter how high -or not- Gladio might be able to shift him.

"Alright. Let's have this almighty leg-up of yours, then."