The [Lesion] has been my main hoe since the beginning, every new player should make it one of their goals to craft it, you get lots of mastery on the way to craft it and it's just a wonderful ugly toxic stick, what's not to love?

Update 36: Jade Shadows

With the changes of this update, bleed damage won’t be the end-all-be-all.
While bleed damage wasn’t nerfed directly, mobs' armour was severely reduced (2.7k cap) and to keep the mobs’ EHP around the same amount, their HP was increased.
In practical terms, more HP, longer TTK(Time To Kill) with bleeds.

Despite that, I’ll keep this build focused on what the [Lesion] does best, Status Damage, in particular, Bleeds(Slash Status Effect) and Poison(Toxin Status Effect)

After the changes, the [Lesion] will work:

Best Vs:
Narmer (Weak to Slash and Toxic)
Infested (Weak to Slash)

Ok VS:
Corpus: While weak to neither. Toxic and Poison bypass shields, doing damage directly to their health
Grineer: It will still make them Bleed.

Mods Breakdown

[Twirling Spire] Neutral combo gives us, Slash, Lift and Knockdown.

Condition Overload If you don't have it use Pressure Point

Blood Rush If you don't have it use True Steel

Organ Shatter self-explanatory

Weeping Wounds gives us that high-status chance -> more procs -> more chances for slash/toxic procs -> more damage.

Berserker Fury If you don't have it use Fury

[Spring-Loaded Blade] If you don't have it use [Reach].
It does nothing for our single target damage but helps with mobs
If you are OK with the [Lesion] default range, you can drop it and put [Buzz Kill](or [Carnis Mandible] cuz it’s cheaper and easier to get)

[Gladiator Might] Here ideally goes a Faction mod i.e.([Smite Grineer]) as they double dip. But given that this is a “lazy” build. GM will do alright.

Unique Trait

The [Lesion] has the unique trait Frenzy:

"Melee status effects grant +15% attack speed and +100% Toxin Damage for 6 seconds"

The additional Toxin damage added will combine with any primary elements (or secondary elements with Toxin) on the weapon.

Q&A

• Why are you not using Prime X version of some of these mods?
  The build is for “mid-game” If u have any of them and want to spend the forma to make them fit, go for it.

• No Elemental Mod?!
  While true a single elemental mod could give us an additional multiplier. It could only buff our Toxic damage.
  On the other hand, we could swap [Gladiator Might] for a Slash mod, which could give us more frontload damage and toxic damage, but could do nothing for our bleed.
  Up to you

• DOTs without Viral?
  It’s 2024, make yourself a favour and get yourself a Primer, ideally at the very least Viral + Magnetic. Viral for HP and Magnetic for Overguard, and watch the Leson go to work.

Closing Words

Take the damage shown here with a grain of salt, as it doesn’t factor DOTs(Damage Over Time) which is the bulk of our damage.
Nor does it show the +100% Toxic damage.

This build will work in most content but will struggle with Acolytes and similar "Status immune/cap" mobs.