Probably the most solid build I've tried on Yareli.

Recommended weapon is the Tenet Cycron: https://overframe.gg/build/646647/
This is because with [Yareli]'s passive the [Tenet Cycron] reaches over 100% Crit Chance.

Don't want to die? Just say no. Merulina provides 90% damage reduction. You are invulnerable while mounting or dismounting Merulina, so you can keep that reduction up permanently.

Sea Snares are an amazing ability to spam, and with Merulina spamming them too you can nearly double your damage output.

Generally, I like using Incarnon Secondary weapons with [Yareli] at the moment. The [Atomos] and [Despair] are currently two of my favorites, with the [Tenet Cycron] taking a third place.

Exilus Slot has only 1 option unless you want to use an umbral forma here, and that's [Power Drift]. The extra Ability Strength is nice, and outperforms almost any other option.

The Aura is [Corrosive Projection]. This is mostly to just lower the amount of armor we have to get through as most of our secondary weapon choices don't have access to a Hunter Munition mod to allow a Viral Slash build. Armor isn't as big a deal as it used to be however, so if you feel like it, you can easily take [Energy Siphon] or [Pistol Amp] instead.

For mods, we have [Augur Secrets] and [Umbral Intensify] for Ability Strength. This allows us a lot of damage on all of our abilities, but more importantly, about 14,000 health on Merulina.

For tankiness, we have [Umbral Vitality] and [Adaptation]. [Augur Secrets] also helps here a bit due to the set passive. Merulina tanks 90% of damage we take, and on top of that, [Adaptation] still stacks on top of that, meaning as long as we are on Merulina we take little to no damage. [Adaptation] here honestly can be unranked, or even removed, if there is a mod you would like to use instead.

Helminth: Now that [Loyal Merulina] exists, we can Helminth over our Sea Snares OR Aqua Blades. I personally use Nourish to apply another damage type to any secondary that I use, as well as increase energy [Regen]! I have eventually settled on Aqua blades as a better Helminth Slot due to it having static damage that doesn't scale without the augment.

And to ensure that our abilities are always castable, [Energy Nexus] and [Primed Flow]. Not much to say here, other than change [Energy Nexus] to [Streamline] if you are not Helminthing Nourish.

Archon Shards: With this build, I highly recommend Archon Shards go to either 3 Armor and 2 health, or 3 armor and 2 emerald for full armor strip on corrosive.