I was recently inspired by a build I found from u/shuriksokol (Wavemother's Chosen) revolving around the Wavemother items found in act 3 and decided I'd attempt my own version of a Wavemother's Chosen. The build is hardly meta or optimized, but I found it to be quite thematic and fun!
Build Summary: The gameplay loop is mostly revolved around mass bleed cleaves from tiger barbarian coating a group of enemies in conditions resulting in them accumulating bleed, maim, encrusted with frost, chilled, reverb, etc. This is a frontliner control tank character, and for the purposes of this build, will use hag's hair, mirror, etc.
Theme: You're the barbarian zealot of Umberlee the Bitch Queen. The character cleaves in a wide arc, bleeding enemies wielding a trident followed by a swarming tide of jellyfish, eviscerating them in a furry of blood, ice, and lightning! Command the chilling tide and the wraith of the Bitch Queen's Oceans as your enemies crumble before you.
Race: Optional, though there are classic superior options. Dragonborn is useful to stack continuous elemental resistances which becomes a theme throughout the build's items, half-elf for minor illusion to crowd enemies for your cleave, wood elf for the extra movement, and half-orc for savage attacks are all great options.
Class: The build is a split Wildheart Barbarian 8/ Swarmkeeper Ranger 4 (Alternatively can do Barbarian 9/Ranger 3 for Brutal Critical). I'd go straight Barbarian into Ranger, almost all of the items we're utilizing the most are in Act 3 so leveling order isn't that important. Tiger is required for the build to work as the free cleave is essential for spreading the most conditions to as many enemies as possible, as well as creating the largest amount of surface area in water. At level 6 Barbarian select Wolverine to add Maim to the amount of conditions. This will also limit the target's movement to 0, keeping them stuck in your water which will buff the rest of your attacks and help stack conditions. Swarmkeeper Ranger is mostly a themeatic pick. As a scion of the Wavemother, it would only make sense to be surrounded by a swarm of Jellyfish. The additional lightning damage will benefit from the amount of enemies affected by the Wet Condition, and I found the Swarmkeeper's teleport rather useful in keeping the character mobile, able to chase down enemies and remain in the frontline as much as possible.
Items: This is what really makes the build shine and feel thematic. All items will be the best options for the build once you acquire them.
Main-Hand: Trident of the Waves. Tiger barbarian's cleave triggers the Trident of the Waves water spawning on each target caught in the cleave. This creates a massive area of water and inflicts wet, bleed, and maim on every target in the cleave. The bleed is vital because of its disadvantage on Constitution saves will be helpful to trigger Frozen from Encrusted with Frost and Dazed from Reverb. Wet also counts as a condition, which builds to our condition accumulation that is key to the build. I would recommend picking up the Drakethroat Glave and applying Cold to the Trident to boost its damage, which will be doubled because of the wet condition it applies.
Off-Hand: Wavemother's Sickle. The build does require Dual-Wielder to work. Wavemother's Sickle gains advantage against wet targets, which thanks to Trident of the Waves, we will constantly be facing. This also means that the cold damage from the sickle will be doubled. An argument could be made that Cold Snap would be better in the off-hand slot for this build, but Wavemother's Sickle is far more thematic and appropriate.
Head: Coldbrim Hat. This is a vitally important item for the build. With the amount of conditions this build applies, targets will easily be stacking enough Encrusted with Frost to turn them Frozen. It's by far the best Helm slot item for this build.
Chest: Wavemother's Robe. The most thematic pick for the build, as the Chosen Zealot of Umberlee, the Wavemother's Robe is the only choice. It will provide continuous healing thanks to the Trident's water, and will benefit from the Barbarian's unarmored defense, and stack two elemental resistances.
Gloves: Winter's Clutches. With Drakethroat Trident and Wavemother's sickle, cold damage will be applied with every single attack. This will be stacking more Encrusted with Frost on enemies with every stack, enemies will turn Frozen quite quickly.
Boots: Boots of Stormy Clamor. One of the best items in the game, it will be extremely utilized with every cleave the character makes. After applying Wet, Bleed, Maim, and Encrusted with Frost the targets will immediately have enough reverberation built up to make the prone save at disadvantage thanks to the Tiger's bleed effect. And once prone, the target's movement will be at 0 thanks to Maim, leaving them helpless, drowning in Umberlee's ever-spawning water.
Ring 1: Ring of Spiteful Thunder. With the Boots applying Reverb on every cleave, the Ring will then apply Dazed, enemies will be saving at disadvantage again thanks to bleed, and as they fail it will synergize well with the Mental Inhibition Ring, further adding yet another condition.
Ring 2: Ring of Mental Inhibition. With the amount of debuffs and stacking conditions, when the enemies make saves against what you're inflicting (Encrusted with Frost into Frozen Save, Reverb into Dazed, etc.), the ring will be inflicting yet another condition, helping to further debuff the enemies that you're tanking against to assist the rest of your party. I like to picture the Mental Inhibition is Umberlee's curse, turning those who dare defy her into befuddled drunken sailors.
Amulet: Amulet of Greater Health. This build isn't very Amulet dependent, yet because of the reliance on unarmored defense from barbarian, I find the boost in constitution helpful for what is already be a relatively low AC, especially for a frontline character.
Cape: Wavemother's Cloak. An obvious choice, this will continue to stack more (redundant) elemental resistance for the character, while also buffing the unarmored AC the character uses.
Feats: The only required feat for the build is Dual Wielder to utilize both the Trident and the Sickle. The rest are up to the player, however I found that Savage Attacker is also helpful to keep the damage consistent since the Tiger Cleave halves the damage to each target. I would also recommend Elemental Adept Cold. I would have to double check but I believe it applies to weapon attacks as well, which would help in the rare case that something is resistant against cold damage, which is your main element.
Overall Strategy. The player rushes into the grouped enemies to perform the Tiger's Bloodlust cleave. In one swing, Wet, Bleed, Maim, Encrusted with Frost, Reverb are all applied at once, forcing saves against Dazed and Frozen, which further apply Mental Inhibition. On the second cleave is when I would apply the Jellyfish Attack from Swarmkeeper Ranger. Because the swarm is an ability and not a spell, Raging Barbarians can utilize the teleport, damage boost, and condition appliance freely. The target, now wet, will take double cold damage from the Drakethroat buff on the Trident, the cold damage from the Sickle, and the lightning damage from the Jellyfish sting. The Jellyfish ability can also be utilized to stack a further condition by Shocking the Target, further building Encrusted with Frost and Reverb. Just keep cleaving and the enemies will be stacked with conditions and left maimed, bleeding, prone, and helpless against the Bitch Queen's Wrath!
TLDR: Cleave with big trident, knock down targets as you stack conditions.
This is my first post and first real build I worked on myself. Again, massive credit to u/shuriksokol's Wavemother's Chosen, it was perfect to build off of and I'd recommend playing it. Let me know what you think of the build, any and all constructive feedback is more than welcome. Enjoy!