Catching up to survivors with frenzy is only good for denying very strong loops. You get put at 120% speed, 125% with addons, your regular speed is 110%, the stun lasts so long that you might as well have walked.

@Juya said:

I don't see frenzy as a killing tool.

Actually, it is great for mobility.(You move so much more quickly and vault faster.)

>

And works great as an elaborate "distraction" tool.

All that mobility let legion:
-Patrol generators(and the map) with ease.
-Catch survivors faster compared to his regular speed. ( You do move faster than them while in frenzy after all.)

You move at 120% MS while in Frenzy, and 110% MS while walking. Assuming that you need to wait some amount of time to fully charge the Frenzy bar, you can use it once per ~6-7s of charging plus the amount of time that Frenzy Run takes (5-6s?). You run in Frenzy with 120% speed, then you have 2-3s of stun, then you walk with 110% speed waiting for a cooldown. For a short distance it is quicker than most of the other killers, but as you said, Legion should be, in your opinion, used for putting pressure by patrolling the map. On the long distance any 115% MS killer can cover bigger distance per minute (especially Billy and Wraith, who can walk with 126% of speed while cloaked) and, of course, Nurse. So Legion is not the best killer to patrol.

-Take a "way around" during the chase to "ambush".(A good example of what I'm trying to say would be: You're chasing a wounded meg in Lery's map/treatment theater, she's getting out of a room and turns right, instead of following her you go the window on the right side of the room and stab her as she crosses the corner and she's down.)

This can be done by any killer, and if you mean you should do this in Frenzy mode, please, remember that you won't down her, you will only put the DWE (Deep Wound Effect) on her/take small amount of the DWE bar.

Deep wound is really useful tool for mostly everything but killing the afflicted survivors.It's main role is to force them of the gens, just like the pig, with her reversed bear trap.And with the ability to reveal any survivor in your terror radius when you inflict Deep-wound, you can easily find survivor on gens and while chasing them the one inflicted with deep wound is too busy mending and healing themselves to work on generators.

When you play Legion, survivors will want to stay as far from each other as possible (at least high ranked ones would do), so because of them working on many generators at one time the genrush is even more efficient. When you manage to find the survivor and stab him, there is a very small chance that you will find second survivor to stab, not speaking of the third one.
But let's say you found the first one, stab him, then found the second one and stabbed him as well. There is no third survivor, so you stab the second survivor again, thus making him sprinting, or you just press M2 to cancel the power, which will stun you. Survivor, thanks to his sprint/your stun gains a distance, the first survivor mended already and is only hurt. You chase the second survivor, that has DWE on him. He, of course, tries to loop you. Then you have 2 ways to end the chase - try to chase him as a 110% MS killer, which would be horrible (please remember, that using Frenzy to catch up to the survivor and then cancelling it is highly inefficient), or you can tryhard to hit the surv 4 times with the Frenzy attack. Both ways takes very long time to down your first survivor, probably much more than average Nurse, Billy, Doc or even Freddy.
And if you say that his ability should be used to waste survivors' time - then I have one question. What's the point in wasting their time (unlimited), while making your chase longer (killer has ~5-7 minutes to win the game), or almost impossible by harming yourself playing trapless Hag/hatchetless Huntress?

@MhhBurgers said:
Butcher+Thana is a pointless combo. You don't want to incentivize the survivors to NEVER heal since never healing is actually a counter to him currently, just rush the gens after mending.

Either you go butcher alone or thana, thana's healdebuff stacks miserably with butcher and puts it just over 30% instead of 25%.

Thanatophobia affects gens too. The problem with the perk is that you need at least 2 people injured at all times to get some benefit. Legion can injure multiple survivors very quickly, and even at base they stay injured for longer because they need to mend. It forces them to heal or else they do gens slower too, which counters the counter to his power in not healing. If you can get all 4 injured then a solo gen takes 94 seconds. Sloppy is more the anti-heal perk, which if you use they just won't heal and then proc Adren and you are borked.

Remember Me works on Frenzy. If the guy has DS, you can get 2 hits from Frenzy, 1 normal hit, get DS'ed, get 1 more Frenzy hit and 1 more normal hit. In one chase you can get 5 tokens really fast. TP also combos well with RM because it can help you slow the game enough to get tokens. Legion can maximize this potentially.

To that end, his perk Discordance would be a good pick to use with TP and RM, since you want to catch survivors in groups this is probably the most efficient way to do that.

Bloodhound I imagined being a good perk for him. Helps with tracking and also beat the "I won't heal" tactics.