Build and weapons demo

Main build

This is the build I use, alternative options for various parts are at the bottom.

[Yareli Prime] has arrived with slight increases to shield and energy, which changes nothing about the build.

This is a Merulina build, if you don't want to ride Merulina you're better off with a different build, or a different frame. Yareli is The Waverider, not The Beachwalker.

Playstyle/Abilities

• Cast 2 to board Merulina
• Find some enemies and cast 1
• Kill enemies using your secondary weapon to proc Merulina Guardian
• Keep moving to keep Yareli's passive 200% crit damage up
• Recast 1 regularly to maintain buff and crowd control (can be cast during battery weapon recharge)
• If you find a nice large group of high damage enemies, cancel and recast your 2 and let them all hit you for a bit - Merulina's health scales with damage received (you are immune) in the first few seconds after casting, so this will give you a tankier Merulina for the rest of the mission. At stupidly high enemy levels (above 6000 or so) you want a slightly less tanky Merulina so that incoming damage will kill Merulina before killing Yareli - recasting is less annoying than reviving. This is not important for tha vast majority of players.

Her 3rd ability, Aquablades, is okay on low levels, but doesn't really do much at Steel Path, so I Helminth over it with Chyrinka Pillar for when I have to defend an objective (like an excavator). You can cast two of these at a time to slow/radiate two lanes of enemies.

The 4 is useful for grouping enemies, which makes killing a group of enemies with the [Dual Coda Torxica] much easier. The 'pull in' part of the ability only applies for a couple of seconds after casting, rather than throughout like [Vauban]'s Bastille ability.

Weapons

[Dual Coda Torxica] (with Magnetic valence):

Riven

(Still rolling, so may change)

My ideal riven would be crit damage, multishot, punch through, then a negative that doesn't matter. Punch through because [Dual Coda Torxica] lacks AoE damage, and it makes killing enemies in a Riptide much quicker.

Cascadia Overcharge give another 300% crit chance when you have overshields, which is what the Augur mods on Yareli are for.

Alternative weapons listed at the bottom.

Primary - Nothing that really helps [Yareli] here. Some people like the [Afentis] for the area buff to reload speed, fire rate and recoil when thrown, but it’s only temporary and I found it annoying to keep dismounting and resummoning Merulina. I use the Dera Vandal because I have a good riven for it and it can use the Soaktron skin, which fits the theme a little.

Melee - any Furax variant with Amalgam Furax Body Count (for secondary weapon fire rate).

Effect of stats

Strength - mostly for the damage increase to enemies captured by Sea Snares, but also increases Merulina's max health and healing done by proccing Merulina Guardian. Strength does not affect the fire rate/reload speed buffs from Merulina Guardian.

Duration - only useful for length of Merulina Guardian buffs, and to recast Chyrinka Pillar less often.

Range - affects how far Sea Snares travel towards enemies, pull distance for Riptide and Chyrinka PIllar radius..

Mods

[Combat Discipline] is used to reliably proc [Merulina Guardian] (which requires Merulina to have taken damage) and Arcane Avenger. If you keep the [Combat Discipline] mod at rank 2 (or below) then you take no damage from it, because 90% of the damage [Yareli] takes is absorbed by Merulina's life pool, meaning only 10% is taken from your life. So you lose 10% of 4 health per enemy killed, which means you lose 0.4 health, which the game rounds down to 0.

Augur mods - Energy spent on abilities is converted to shield and allows you to gain overshield, which is necessary for Cascadia Overcharge to work.

Primed Vigor - I like it, but if you don't, or if you don't have it, or if you want to save forma, substitute it for Augur Accord or standard Vigor. You want enough shield to get your companion above 1200 shields with Link Redirection.

Streamline/Flow? - [Energy Nexus] works better for [Yareli] because the main skills you’ll use only cost 25 energy, and if you for whatever reason lose your Merulina you will want to get back on it as soon as possible, energy [Regen] can save your skin in these situations. Don't take any energy efficiency because you still want to be spending some energy to proc the Augur mods.

Arcanes

Arcane Avenger for crit chance and Arcane Velocity for fire rate.

Archon Shards

Azure archon shards are the only source of armour (3 × 225 armour) that also applies to Merulina. The two emerald shards are so you can fully armour strip enemies with your weapon (2 × 3 additional corrosive stacks, though normal shards will also do).

Companion

I now use a [Sahasa Kubrow] with the following setup:

The important parts are:
Link Redirection - to get over 1200 shield
Reinforced Bond - for 60% increased fire rate now that it has over 1200 shield
Tenacious Bond - for +1.2x final crit multiplier (which is multiplicative with other crit damage mods)
Bite (on claws) - to get crit chance on pet high enough for Tenacious Bond to work
Dig (the reason I switched to the Kubrow) - to help keep up ammo supply on enemies that take a bit more shooting (inspired by a tusk [Thumper]).

Focus School

Doesn't matter at all. I use Madurai so my amp can easily kill void angels etc.

Low investment / New players

If you don't want to throw loads of forma at the stupid k-drive frame, or you're new to the game and can't access the mods used in the main build, or the [Dual Coda Torxica] (which requires a whopping MR17), here is a 0 forma setup and MR2 weapon that works:

[Combat Discipline] (Rank 2) would be desirable instead of [Energy Siphon], but isn't available until Arbitrations (without trading).

For the weapon, I recommend the [Sonicor] (blueprint available on the market)

This setup also uses 0 forma and I've tried to choose mods that are available fairly early on in the game.

Alternative Options

Secondary Weapons

For a long time my favourite was the [Sporelacer] (+ haymaker + macro thymoid) kitgun:

Riven can be swapped for [Lethal Torrent]

Occucor is fun if you have the [Sentient Surge] mod

Riven can be swapped for [Hornet Strike]

[Sonicor] (with higher mods than the above build):

Riven can be swapped for [Hornet Strike].

Arcanes

Other options are:
Arcane Pistoleer
Molt Augmented
Molt Efficiency

Archon Shards

Since the update to how armour works, armour stripping is less important, so feel free to swap out the emerald shards for something else. The Topaz shards that give extra secondary crit chance when killing an enemy with heat status are a good choice.

Companions

I previously used an [Adarza Kavat] with the following setup:

Which is similar to the kubrow but with:
Cat's eye - An extra 60% crit chance for 10 seconds every 20 seconds
instead of [Dig]

If you'd rather use a robotic companion, you could use the [Burst Laser] weapon, and put the pistol augur mods on it, then replace the augur mods on the main [Yareli] build with something else. [Primed Continuity] and [Stretch] would be direct upgrades, but you could also try something like Catalysing Shields if you want to shield gate, since you may not be able to use [Reinforced Bond] anymore (link mods are not available on sentinels, so you'll struggle to get enough shields to activate it). If going shield gating, you may also want to replace [Primed Vigor] as well.

[Loyal Merulina]

Still not an option.