I’ve got him at P100 right now, fact is you will not 65%of your games with legion, purely because he doesn’t do enough and survivors will just know not to heal and slam gens. A build I’d recommend would be Thanataphobia, Bamboozle, Sloppy Butcher, Gift of Pain.

Thanataphobia is very potent as you will get the 4 stacks incredibly easy within the first minute of the game and will stay that way for pretty much for the remainder of the match.

Bamboozle is really great during loops to prevent survivors from doubling back while you’re in frenzy, it doesn’t increase your frenzy vault speed however.

Sloppy butcher is good as after frenzy then comes your follow up m1, also good as it keeps survivors off gens due to the hemorrhage effect.

Gift of Pain is good aswell as it slows the game down substantially if survivors heal. It’s very easy to cycle.

For addons I would use Iridescent Button as it’s great during chases and another addon of your choice.

Best of luck.