As it happens -- as Lancelot probably should have guessed -- it is much easier for him to keep pace with Lan Wangji when wielding his blade one-handed. It also gives him more opportunity to attempt to telegraph his own moves less clearly. He does not have the sort of maneuverability that Lan Wangji's cultivation allows, but he certainly can act with a little less of the expected discipline and more creativity.

It is a very rewarding challenge.

He parries several of those swings, then twists to present his unarmed side while bringing his own blade in with a swing from above.