The new Whispers in the Wall update gave [Saryn] a lot of new goodies in Emerald archon shards and the [Grimoire]. I've also come to appreciate shield gating more. I've largely retired my old healthtank build in favor of this; the result is a build that can scale to max level content due invincibility-based defense and full-armor-strip based offense, and benefits from significantly higher strength/range values than the old build as well.

To play this frame effectively, basically just prioritize spreading spores as much as you possibly can (remember to stack every strength buff you can before applying first spore! it can snapshot for basically the whole game!), using Revealing Spores to make sure you're keeping a good spread going (keep in mind enemies can go from green -> red color simply because they're still in radar range but not the augment's 40m coloring range...this scales with range tho so more like 106m). Aside from that, keep your buffs/energy up (including Zenurik bubble! important for nourish energy gen) and don't die. That's about it. In practice, since you have so much energy from Nourish and enemies will be dying so rapidly, you will likely find yourself jumping around spamming Miasma. Spores will do the rest of the work. If you have access to a good Grimoire, then you'll probably want to weave that in; either energy orb/defense strip on kill, paired with either Strength buff/energy regen on alt-fire. Oh and if your shield goes down spam abilities to get it back (preferably 4, as it has the most impact). Don't forget a cast speed archon shard to make this fast enough.

ARCHON SHARDS ARE VERY IMPORTANT.

With 2x base emeralds u can get +4 max corrosive stacks meaning you can full armor strip with spores and any corrosive weapons you may have. 1x Tau will get you to 98% strip at 13 stacks, but sadly that last 2% is the most important so imo that does not cut it.

You also need 1 cast speed shard (preferably tauforged) for your cast anims to actually be fast enough to support a shield gate playstyle.

And 1 or 2 tauforged emeralds to give +15% ability damage to enemies affected by corrosive is kind of a no-brainer. I've tested this can can confirm it works as you might hope, it's just a new multiplier, and will increase your final damage by the listed amount. fun to watch actually, on full stripped enemies your spore counter will say 1000 but you'll see ticks of 1150 damage thanks to the +15% :p

It's not quite as good as it sounds cuz you have to give up +15% str to get it, weaking all your abilities. Even lowers corrosive status chance of spores, delaying full strip. But it's still definitely best in slot for damage unless your strength is already really low.

if you used 2 you're already out of slots; if not, your one remaining slot should probably go towards +Str, as just mentioned.

The 2 +corro stacks shards also apply to your weapon damage as well, mind. So Venom Dose becomes a stronger consideration than usual, and quick-application corrosive weapons gain a lot of stock as well (might I recommend [Boar] Incarnon and augmented [Ocucor]?)

Why Nourish? Because the energy gain is just too damned good. You'd think Roar multiplying our spore damage by like 60-90% would be the clear play if we wanted to maximimize AoE carnage, but I've found that in practice the sheer windfall of energy Nourish provides actually manages to dwarf this. That's for two reasons: one, it frees up mod/arcane slots allowing us to crank that Strength stat even higher; this, along with the Viral weapon/defense buffs from Nourish handily makes up for the damage loss of losing Roar. Two, even with all those freed slots now occupied by strength boosters, Nourish still very handily out-energy-regens an Equilibrium/Energize build and allows you to be much, much more spammy with your abilities. This pays off in spades, as your newfound ability to spam the shit out of Miasma is absolutely key to keeping the spore spread going full steam ahead. Your high str/range will allow you to build your spore damage rapidly, to the point where enemies start dying extremely quickly, and you can only just barely manage to jump around spamming Miasma fast enough to keep the enemies from dying faster than you can spread, lol. Without Nourish, this doesn't really happen, and you're always kind of worried about your energy. Honestly, there's an argument to be made for dropping even Primed Flow from this build to crank it even more. My first time testing this out in a solo SP Circulus (lv 180-200) I did about 11 min and came out of it with a 20k spore counter and 2700 kills. It's nuts.

Extra notes about surviving via shield gating:

• Catalyzing Shields isn't used because 45% eff + 190% energy -> shield + spammable 50/75 base cost skills (the latter of which applies an AoE stun) allow for large chunks of shield regeneration. Miasma restores 220 shields, and Toxic Lash/Nourish restore 147. [Saryn]'s base shield of 370 gives a 1.37s gate at full (slightly larger than the [Catalyzing Shields] 1.33s gate), and the 220 you get from 1 Miasma cast already gives a pretty healthy 1.07s by itself (0.9s for the other two abilities). Just doesn't seem worth the slot when you consider you can get an almost-as-good gate on-demand (that AoE stuns, remember) without it, and an even better one by using more than 1 skill.
• Even if you slip up and die, this build primes you very well for Last Grasp revival, even on a weak school like Zenurik. Upon being downed you are likely surrounded by enemies with their armor stripped and already dying to spores. Just shoot em as operator and you'll be right as rain.
• You can still use [Catalyzing Shields] to gate if you want, just means you'll have to drop another slot. It does improve your consistency, I just found it unnecessary and prefer the extra power boost from another mod slot freed up.
• Alternate helminths can also help. Nourish is already an excellent ability for shieldgate builds, but Breach Surge is another good consideration; heavy CC, big damage amp, and you can chain cast it (cancel breach surge cast animation with any of your own abilities) for big shield gains + big effect. (Roar is the main other helminth I'd consider, but it is not very helpful in terms of survivability.)

As for arcanes, Augmented and [Vigor] if you're using Nourish, and Energize over one of them instead.

Oh also, I recommend pairing with a [Duplex Bond]'d [Dethcube] (I use Gas [Verglas] to spread assists). Helps with energy economy more.

Alternate good mods include [Transient Fortitude], [Primed Continuity], [Augur Secrets], [Energy Conversion], [Venom Dose], or [Catalyzing Shields]. You can replace [Primed Flow], [Cunning Drift], or [Revealing Spores], I suppose.

Anyway, put this all together and you will have a comically lethal AoE damage + weapon platform frame that can consistently thrive in any level of content. Emphasis should be placed on the absurd level of AoE damage this frame can consistently vomit while still being able to handle literally infinite damage thrown at her. She doesn't sound that good when you just say "she does a lot of damage and doesn't die," so to be clear she does absolutely insane unrivaled constant map-clearing kinds of damage. She's one of my top frames for a reason. When you need that kill counter to be as high as you can possibly get it, accept no substitutes.

Edit 12/26/23: Replaced [Transient Fortitude] with [Cunning Drift]. Max range is very helpful and getting some duration back makes the build a lot comfier too. You can make up for the lost str by stacking a [Grimoire] str buff before applying your first spore, if you'd like.