Xerath vs LeBlanc Mid Matchup
Xerath Mid wins 49.2% of 1,624 Low Elo games against LeBlanc Mid, -2.4 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
How to play as Xerath
Keep Shocking Orb (Xerath E) for LeBlanc's Distortion (LeBlanc W) entry rather than spending it casually; if her dash is unavailable, use Arcanopulse (Xerath Q) and Eye of Destruction (Xerath W) to keep her at range.
Arcanopulse (Xerath Q) reaches farther than Sigil of Malice (LeBlanc Q), but Distortion (LeBlanc W) gives LeBlanc a way to close distance quickly when Xerath is committed to casting.
Shocking Orb (Xerath E) is Xerath's key stun threat when LeBlanc uses Distortion (LeBlanc W) to enter, so the trade often turns on whether LeBlanc can sidestep E after landing.
How to play as LeBlanc
Look for Distortion (LeBlanc W) while Xerath is committed to Arcanopulse (Xerath Q), then sidestep Shocking Orb (Xerath E) before following with Ethereal Chains (LeBlanc E); do not walk straight into the held stun.
Sources
These notes come from r/LeBlancMains, checked against the champions' abilities.