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. Aqua Blades are a guaranteed stagger, while Merulina provides 90% damage reduction. You are invulnerable while mounting or dismounting Merulina, so you can keep that reduction up permanently.

Use Viral from your secondary weapon as a primer, and let Aqua Blades do the rest. Works in steel path (Especially in steel path) with no issues provided you group all enemies. Luckily, [Yareli] has that covered too with her Riptide.

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.

Aura is [Pistol Amp], since [Yareli] is a frame that is restricted to her secondary most of the time.

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.

Finally, for duration to help our Aqua Blades, we have [Primed Continuity]. If you want more, you can replace [Augur Secrets] with [Augur Message], which adds about 10 seconds to the duration.

Helminth: Now that [Loyal Merulina] exists, we can both Helminth over our Sea Snares AND still get the benefits from them as Merulina will fire them even if they are helminthed away. I personally use Nourish to apply another damage type to any secondary that I use, as well as increase energy [Regen]!

And to ensure that our abilities are always castable, [Primed Flow] and [Streamline]. Not much to say here.

Archon Shards: With this build, I highly recommend Archon Shards go to either 3 Armor and 2 health if using Azures, or Duration, if using Crimson.

ANOTHER big buff to [Yareli], as Shields and Shield Gating have been buffed! It now takes even longer to smash through her defenses!

If you REALLY like using the K-Drive bit, just replace [Loyal Merulina] with [Surging Blades], and keep Sea Snares instead of putting Helminth over her 1st ability.