Nephenee

This (somewhat budget) set makes an ATK boon Nephenee an extreme threat for both phases and makes her work well as a melee tank, even more so once her health is in range of the Brazen and Wrath skills.

The only weakness for this set is that Nephenee is highly dependent on the Brazen skills in order to be effective and thus, she may take endangering damage and cause the Brazen skills to be entirely redundant.

Alternatively, Nephenee's seal can be changed to Atk/Def Bond 3, allowing Nephenee to consistently have a boost to her Atk and Def as long as she's near a teammate. If this seal is chosen, Atk/Def Oath 3 can be considered for her C skill to further compliment the bond skill.

The ideal boon/bane stat for this is either +ATK or +SPD and -HP, -HP is ideal as it enusures that Nephenee can reach the threshold for Wrath and the Brazen skills more easily. ATK boon ensures that Nephenee can kill armored foes better while the SPD boon prevents more follow-ups from ,otherwise, speedier foes.

A budget Nephenee I use for AR.
I refined Dauntless Lance for +def as her speed is already quite high and I use her often on the player phase so I figured it would overall be more useful for me than the effect.
I replaced her Moonbow with Bonfire as the special cooldown charge is already low thanks to Dauntless Lance and it deals a lot of damage with her 45 def.
Fury gives her additional stats and the 6 chip damage helps her activate Wrath faster, and I've found attack smoke to be useful when she's left in a lot of foes' range in the enemy phase.
Panic Ploy is mainly there for her to help teammates via debuffing and to make further use of her good HP.

A few days after I started playing this game, Nephenee joined my party, and she has remained among my most reliable units ever since. I also got her far before I got to use any Armored characters, and basically everyone I pulled back then was either a purely offensive unit, inherit fodder, or totally useless. Nephenee filled a role I desperately needed someone to fill: Tank. And yet, she proved to be far more than that. Nephenee is immediately decent out-of-the-box, but with a bit of investment, she can easily go toe-to-toe with the best of them... except mages.

Let's get Assets/Flaws out of the way as it is the least interesting to discuss. Nephenee excels as long as her Flaw is either Res, or HP. An Asset in any of the other stats will do just fine, especially with this build. Now on to the fun stuff!

Starting off strong, we have her refined Prf. While there are definitely more OP Prfs out there, Nephenee's serves her perfectly, allowing her to threaten most Armored units(even some green ones!), and boosting her best stats in Enemy Phase. It also accelerates Special trigger cooldown by 1. Simple, yet effective.

While many would regard Reposition as the best movement-based Assist, I would disagree when it comes to low mobility teams, and Armored/Flying/Infantry Tank units. Nephenee is of the latter, and Pivot proves to be unbelievably useful for her. It can effectively give her up to 2 more spaces of movement, and allows her to get in front of her allies, protecting them from a slew of threats. Of course, Reposition works as well, and Swap is a sort of budget version of Pivot with some other utility purposes.

I bet you expanded this build because you saw Blue Flame and went "WHAT?!". Look, she's built to be a Tank. Which means she is likely to be adjacent to at least 1 ally, and if not, she'll be close enough to easily set it up. I understand Blue Flame is a high investment skill, so don't worry if you can't afford to feed her an Owain. Bonfire, Moonbow, Luna, and Aether are all solid choices as well for this build. Aether can be especially fun. While it can take away her Wrath, it would provide more survivability if that is preferred. Still, if you can afford it, Blue Flame won't disappoint. With Wrath active, it deals +35 guaranteed damage when next to an ally. OUCH!

Steady Posture 2 is obviously the same as her weapon's refined effect. We're doubling up these in-combat boosts because they are by far her most important skills. If there is ever a Brazen Spd/Def, that would be better, but unfortunately, we'll have to settle for a +4/+4. A Steady Posture 3 is more likely to be added to the game at some point so, might be worth giving this to her anyway.

Wrath is the only base kit skill we're using, though there are alternatives if you aren't using Moonbow or Blue Flame. Guard and Vantage prove to be handy, as well as Windsweep if you want to go full Tank Mode, as her Spd hits a respectable 43 at base with double Steady Posture 2 active, 50 with a Brazen Atk/Spd 3 seal added to it.

Her C skill is flexible. I have Atk Smoke 3 as it further improves her survivability, even against magic users. Def Smoke is another worthy skill as it would help make up for her slightly lacking Atk stat. Other options such as Drives, Tactics, and Waves can be fun to play with too.

Finally, her Seal. This too, is flexible for this build. I gave her Brazen Atk/Def as it boosts her middling Attack and further cranks up her Def. Literally any Brazen is useful to her, including the Atk/Res one, as even she can appreciate a bit of extra magical bulk. Darting Stance, Fierce Stance, Atk Smoke, and Spd Smoke are excellent, and Fortress Def might be worth considering if you have an Atk Asset to counteract the reduction it comes with. If all of those are either attached to other units, or simply off-the-table, Bonds will suffice, especially if you're using Blue Flame.

Never forget, Nephenee is actually rather versatile. She can comfortably perform offensive roles, as well as a number of different defensive roles, thanks to her preference in both Spd and Def. I've only shown you one type of defensive role. That of a speedy, deadly Tank. She's beauty, she's grace, she'll lance you in the face!

In this build you maximize the damage output as much as you can/want.

Pretty straight forward build, Nephenee will be eating her own HP with Fury, entering in Wrath range, stricking with Aether rather easely thanks to Heavy Blade and her high Atk and recovering her own HP with Aether for a better sustain. You can also run Moonbow or Glimmer.

C slot is pretty flexible, but Threaten Def can help making near enemies more squishy.

Nephenee's build allows her to trigger her special and trigger it fast. She's sufficiently fast to often secure doubles. The Dauntless Lance lowers her special cooldown from 2 to 1, and Quickened Pulse lets her start battle with her special ready, killing foes or setting her up for another special if the enemy survives. Threaten Spd is used to help her get doubles.