Tip overview

Just practise strafing and pray to god that he has bad aim.

In Pursuit checks who is closest with each shot. If you manage to fight him in a 2v1, alternate who is closer or have the person with the highest health stay in front to protect the person in back.

Beware of his ultimate, although he is not immune to CC and is moving slow while using it, it leaves you a small window to strike him, watch out for every indicators which indicates that he is near you, if it's a bad match up leaving is easier.

Lex has no crowd-control and medium range. Focus him as much as possible to get him out of his comfort zone.

Use Pursuit only when the enemy is low on health since it doesn't do as much damage and if you don't kill them with it you could possibly die,since you are vulnerable and aren't doing as much damage to kill them.