Xerath vs Nami

Charge Arcanopulse (Q) to poke from long range: its range grows with the charge, but you slow down by up to 50% in the meantime.

Slow your target with Eye of Destruction (W) before Arcanopulse (Q): the center of the zone slows the most, and a slowed target dodges poorly.

Land Shocking Orb (E), then center Eye of Destruction (W) on the target: stunned, they can't dodge it, and the center slows the most.

Cast Rite of the Arcane (R) to finish a fleeing target or support a distant fight: your shots reach 5000 range, with bonus damage per champion hit.

Change direction when she casts Aqua Prison (Q), then step up if she misses: it's her only stun outside her ult, on a 12 to 8 second cooldown.

Avoid trading when she casts Tidecaller's Blessing (E) on her ally: their next autos and abilities slow you and deal more damage.

Step out to the side of Tidal Wave (R): it travels a long way but moves slowly, and its slow lasts longer the more distance it has covered.

If you can engage, target Nami when she steps up: with no dash or leap, she can only walk away.