Eleonora

Preferred IVs: +SPD or +ATK / -HP or -DEF or -RES

• For more frequent follow-ups and, more importantly, activating the counterattack disruption effect of Mirage Longbow, Speed will be this build's best Asset.
• Attack is not bad to fall back on should Speed not be available.
• A defensive stat of choice should be taken as a Flaw at zero merges.

Weapon: Mirage Longbow

• Mirage Longbow effectively puts Eleonora at the top of the food chain as far as Firesweep Bow users are concerned.
  • Compared to the normal Firesweep Bow, it has a superior Might of 14 and built-in additional 3 Speed.
  • Eleonora is required to win Speed comparisons against her opponents to activate its "sweep" effect. However, considering Eleonora's resulting stat after +3 Speed and her A-slot skill on top of her naturally fantastic Speed, this is almost a mere formality.
  • As the previously mentioned counterattack disruption effect is player phase-only, Eleonora has the option of counterattacking the opponent herself if she must.

Assist: Draw Back / Rally Atk/Spd+/ Reposition / Flexible

• For general purpose gameplay, Draw Back and Reposition generally are beneficial for Eleonora's teammates as it typically rescues them from bad enemy range.
• Rally Atk/Spd+ comes by default on Eleonora. It is an option for Coliseum scoring (due to its higher SP value than other Assist skills) and general team support if Eleonora's allies are lacking in visible Attack or Speed bonuses.

Special: Luna / Moonbow / Dragon Fang

• Physically bulky enemies are some of Eleonora's poorer matchups, which is where Luna comes in as it turns their high Defense stats against them. Due to Mirage Longbow's counterattack disruption, Eleonora is generally given good opportunities to charge it up in three hits.
• Moonbow pairs well with Flashing Blade as Eleonora can potentially activate it in two attacks in a single round. Otherwise, it is a reliable but weaker choice compared to Luna.
• Dragon Fang acts as a nuclear option as it scales reliably well off of Eleonora's great invested Attack. However, its rather inconvenient cooldown value of 4 means Special acceleration in some form (such as Flashing Blade or Infantry Flash) is crucial for practical activation timings.

Passive A: Atk/Spd Push 4 / Swift Sparrow 3 / Life and Death (3 or 4) / Atk/Spd Solo

• Atk/Spd Push 4 provides immense in-combat offensive boosts of +7 to Eleonora's Attack and Speed, and even comes by default on her base movekit.
  • The offensive boosts also work in enemy phase, which Mirage Longbow thankfully allows Eleonora to partake in if necessary.
  • Unless you are exceptionally concerned about it stopping working below 25% HP, it acts as a great default A-slot skill.
• For more consistent options (as Push has a negative HP threshold), users may be more inclined to other options.
  • Swift Sparrow 3 works exclusively in player phase (which is where Eleonora does much of her work anyway) and provides an only slightly less potent boost of +6 Attack and +7 Speed.
  • Life and Death drops Eleonora's defenses at the cost of having consistently working offensive supplements. Its maximum level (4) provides exactly the same boosts as Atk/Spd Push 4.
  • Atk/Spd Solo only requires Eleonora to be away from allies to provide its nice +6 boosts. Though the condition is easy, there is no guarantee Eleonora will always be in correct conditions to fulfill it.

Passive B: Lull Spd/Def / Spd/Def Ruse / Chill Spd / Poison Strike

• Lull Spd/Def further addresses Eleonora's hatred of high Defense enemies by applying a constant Defense reduction of -3 in addition to cancelling Defense bonuses. Additionally, the Speed portion of the skill helps Eleonora fulfill her weapon's counterattack disruption effect by skewing Speed comparison in her favor.
• Chill Spd passively debuffs the Speed stat of an opposing superunit by -7 at the start of every turn. It is far easier to access than Lull Spd/Def and provides team support as Eleonora's other allies benefit also directly from fast enemies becoming far more manageable.
• An obvious pair-up with Rally Atk/Spd+, Spd/Def Ruse also comes by default on Eleonora's kit and is an option for team support and Eleonora's own benefit (assuming other allies use Rally skills on her).
• As Mirage Longbow prevents counterattacks on slower enemies, Eleonora can use Poison Strike to inflict further punishment on bulky enemy that survive her onslaughts. Against frail enemies that are already heavily damaged if not outright defeated, however, Poison Strike's value tends to waver from there.

Passive C: Spd Smoke / Def Smoke / Atk/Spd Oath / Flexible

• The C slot is open to the player's own choice, and Eleonora doesn't come with one of her own. A Smoke skill is generally a safe bet due to Mirage Longbow's safe initiations and pairs well with refresher units so that Eleonora can make use of debuffs.  
• If inheriting Swift Sparrow 3 from Legendary Celica and Eleonara has inherited its second version prior, she has the option of also inheriting Atk/Spd Oath, which helpfully provides +5 Attack and Speed bonuses if next to an ally.

Sacred Seal: Swift Sparrow / Darting Blow / Flashing Blade / Poison Strike

• Swift Sparrow further builds on the most important parts of this build, but Darting Blow can be taken for its higher exclusive Speed boost should fulfilling Mirage Longbow's effect be a priority.
• Flashing Blade is an excellent option when paired with even-numbered Specials; Moonbow can typically activate within a single round while Dragon Fang is simply a more practical nuking option all-around.  
• For reasons stated in its B slot section, Poison Strike is considerable here. It is worth noting that Eleonora isn't suffering from many opportunity costs running this as a Sacred Seal as opposed to potentially dismissing other B slot options (such as Lull Spd/Def).

Preferred IVs: +ATK or +SPD / -HP or -DEF or -RES

• AOE Specials measure the visible difference between Eleonora's Attack and the opponent's Defense. Since Attack also benefits massively from a superasset value, it is preferred as an Asset for larger Special and one-hit damage.
• Though less potent than Attack on this build, a Speed Asset more effectively fulfills Mirage Longbow's Speed comparison condition, as well as potential for follow-up attacks should the AOE Special fail to do enough prior damage.   

Weapon: Mirage Longbow

• Though it lacks cooldown acceleration (meaning Eleonora otherwise doesn't have to rely on Blade skills to have her Special ready after Special Spiral), Mirage Longbow's counterattack disruption still gives Eleonora a lot of potential in the AOE spamming department.
  • Assuming Eleonora fulfills conditions as she should and the opponent lacks Null C-Disrupt, Mirage Longbow protects her from counterattacks entirely. Thus, matchups are generally safer, especially in situations where Eleonora may whiff one-hit KOes.
  • Notably against Vantage users, Eleonora does not have to equip Hardy Bearing like other AOE Special users such as Ophelia usually do.

Assist: Draw Back / Reposition

Special: Blazing Wind / Other AOE Specials

• The AOE Special used is up to the player, though Blazing Wind gets worthy praise above others as it deals increased damage (1.5x) against foes and their adjacent allies—a scenario that is typical as AI-controlled units tend to group up for Rally support.

Passive A: Life and Death (3 or 4) / Fury (3 or 4) / Flashing Blade 4 / Heavy Blade 4 / Atk/Spd Push 4

• As in-combat offensive boosts won't be optimal on this build—AOE Specials take visible Attack into account when calculating damage—options fall typically between Life and Death or Fury.
  • Life and Death grants the highest potential visible Attack and Speed boosts in exchange for dropping defenses. Though, the drawback isn't really a problem when initiating against slower enemies thanks to Mirage Longbow preventing counterattacks.
  • Fury provides visible stat padding all-around including Eleonora's defenses, which allows for safer stray attack tanking (especially for Aether Raids Defense). The recoil suffered after every successful round of combat also helps Eleonora benefit from Wings of Mercy support more often than not.
• A Blade in the A-slot is technically slightly inferior to themselves in the Sacred Seal plus a more potent A-slot skill like Life and Death. However, it saves up on Sacred Seal usage if Flashing Blade or Heavy Blade is a commonly wanted Seal in your barracks.
  • Furthermore, the true damage granted by a Blade 4 skill conveniently applies to AOE Specials, making them roughly as effective as Life and Death 3.
• Atk/Spd Push is still a great default to fall back, though its in-combat offensive boosts will not be considered when calculating AOE damage, leaving Eleonora mostly reliant on the killing blow(s)'s damage than that of her Special.   

Passive B: Special Spiral

• After every activation of Eleonora's AOE Special, Special Spiral fulfills half of the charge necessary to abuse it again. Combined with a Blade skill (which charges by 2 on the last hit), Eleonora can instantly have her AOE Special ready to pop again.

Passive C: Savage Blow / Def Smoke / Any Self-buffing skill

• For further punishment on adjacent enemies after an activated AOE Special, a Smoke-type skill is yet again considered. Savage Blow deals a decent amount of nonlethal damage after combat and can potentially weaken into KO range, whereas Def Smoke performs similarly but targets Defense instead.
• Self-buffs such as Attack-based Waves or Joint Hone skills may be taken to self-sufficiently improve Eleonora's combat. Otherwise, the skill taken in this slot is up to your team preferences and current resources.

Sacred Seal: Flashing Blade / Heavy Blade / Swift Sparrow / Atk Spd 2

• The combination of a Blade skill and Special Spiral—assuming both skills are properly activated—allows Eleonora to have her AOE Special ready after every successful use. Otherwise, Eleonora will be left typically with 1 CD away from a prepared Special. In other words, Flashing Blade or Heavy Blade in some form is pretty much necessary on this build.
• If a Blade 4 skill is used in the A slot or Blade support is outsourced (through skills like Infantry Rush or Infantry Flash), Eleonora can fall back on Sacred Seals such as Swift Sparrow or Atk/Spd 2 to directly improve her offensive stats.