Alexiel (Summer)/Strategy

Strengths

• Mirror-Blade BarrierDEF is boosted (Stackable / Can't be removed)
  is an unremoveable, permanent buff that increases all allies' defense. It stacks by itself up to 45%.
• Can redirect all damage with  Uncrossable WatersRemove all debuffs from Alexiel.
  Gain Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  Duration: Up to 3 turns. (Consumes 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  every turn. Ends when no Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  are deployed / Max: 3 turns). It not only redirects all-ally attacks from foes, but greatly enhances her sustainability by converting all elemental damage to Water, capping Water damage at 1500, and boosting her defense and debuff resistance.
• With one click,  Nibelung SandInflict 20% Water ATK DownWater ATK is lowered
  Strength: 20%Base Accuracy: 100%Duration: 180 seconds and GravitySpecial attack max charge turn is extended
  Base Accuracy: 100%Duration: 180 seconds on all foes.
  When 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  is consumed: Also inflict Accuracy LoweredAttacks and special attacks have a chance to miss
  Base Accuracy: 100%Duration: 2 turnsLocal status effect. debuffs foes with 20% Water ATK DownWater ATK is lowered
  Strength: 20% and GravitySpecial attack max charge turn is extended
  with 100% base accuracy.
  • Consuming Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
    will also inflict Accuracy LoweredAttacks and special attacks have a chance to miss
    Local status effect on foes, potentially causing foes' attacks to miss.
• Becomes stronger with her self-buff, Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  . This status is different from her grand version - in this version, having 3+ Mirror-Blades deployed will heal her for 10% of her max HP, up to 1000 HP.
• Possessing both sabre and katana specialty means that she's very flexible to put in Earth Atma/Ultima parties, since most of them are either sabre- or katana-centered.

Weaknesses

• Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  's micromanagement requires Alexiel to frequently C.A. to regain her Mirror-Blade stacks, and she can't buff her own multiattack rate.
• By casting  Uncrossable WatersRemove all debuffs from Alexiel.
  Gain Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  Duration: Up to 3 turns. (Consumes 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  every turn. Ends when no Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  are deployed / Max: 3 turns), she can potentially receive up to 1500 damage times allies present in front line, if the foe uses an all-ally special attack. Unfortunately, her buff doesn't convert plain damage; casting  Uncrossable WatersRemove all debuffs from Alexiel.
  Gain Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  Duration: Up to 3 turns. (Consumes 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  every turn. Ends when no Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  are deployed / Max: 3 turns) means that she'll eat all plain damage on her own.

Characters

Earth Sword characters for Atma Sword compositions: Aletheia, CaimPossible due to his  Wild CardSubject to all specialty weapon-, style-, and raceOfficially called "type" in-game-related weapon skills.., De La Fille (Earth), Siegfried, Threo, Vira (Summer).
Earth Katana characters for Atma Blade compositions: Aletheia, CaimPossible due to his  Wild CardSubject to all specialty weapon-, style-, and raceOfficially called "type" in-game-related weapon skills.., Cain (Grand), Eahta, Narmaya (Holiday), Siegfried.

• Baal allows her to tank often and gain multiattack buff from his  SessionGrant SessionMultiattack rate, DEF, and hostility are boosted / Deals bonus earth DMG for one-foe attacks (Can't be removed)
  Duration: 5 turns to caster and an ally. (Can't grant Session effect to more than 1 other ally at a time.). When Alexiel's Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  is active, SessionMultiattack rate, DEF, and hostility are boosted / Deals bonus earth DMG for one-foe attacks (Can't be removed)
  further reduces damage she can receive, eliminating most threats with both buffs.
• Lobelia can reduce the cooldown of Alexiel's  Uncrossable WatersRemove all debuffs from Alexiel.
  Gain Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  Duration: Up to 3 turns. (Consumes 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  every turn. Ends when no Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  are deployed / Max: 3 turns) with his  Warbringer900% Earth damage to all foes (Damage cap: ~1,120,000).
  3-turn cut to Earth allies' skill cooldown.
  (Consumes 5 Magic CrestMagic is amplified (Can't be removed)
  .)
  At level 75:
  Damage increased to 1000%, provides very high uptime of protection for party.
• Rosetta (Summer)'s buff from  Blue Rose BarrierGain Blue Rose BarrierBoost to hostility / Immune to DMG stacked up to a fixed amount / Grant buffs to all allies every turn based on Rose Barrier's strength (Ends upon exceeding fixed amount of DMG) (Can't be removed)
  Duration: Indefinite and a shield effect worth 70% of caster's max HP (Max: 4000).
  (When shield effect ends: Blue Rose BarrierBoost to hostility / Immune to DMG stacked up to a fixed amount / Grant buffs to all allies every turn based on Rose Barrier's strength (Ends upon exceeding fixed amount of DMG) (Can't be removed)
  Duration: Indefinite ends.) increases her hostility, but Alexiel's  Uncrossable WatersRemove all debuffs from Alexiel.
  Gain Uncrossable WatersReceives all attacks in place of allies (Includes all-foe all-ally attacks) / DEF and debuff resistance are boosted / Elemental DMG from foes turns into water DMG / Water DMG taken is capped at 1500 per hit / Ends when no Mirror Blades are deployed (Can't be removed)
  Duration: Up to 3 turns. (Consumes 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  every turn. Ends when no Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
  are deployed / Max: 3 turns) completely negates the effect. The result is the buff duration will be increased and the strength will reach the cap more constant, which benefits the party as long as her shield doesn't break.

Weapons

• Ultima Sword/ Ultima Blade: Can substantially increase Alexiel's multiattack rate with Gauph Key of Strife.
  • Gauph Key β boosts her  Hildebrand400% Earth damage to all foes (Damage cap: ~630,000).
    All allies gain Mirror-Blade BarrierDEF is boosted (Stackable / Can't be removed)
    Strength: 9% (Max: 45%)Duration: Indefinite (Stackable / Max: 5).
    Deploy 1 Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
    Duration: Indefinite. damage cap, which activates frequently after charge attack.
  • Gauph Key γ is overall very useful to boost her C.A. Damage cap, which is granted by her ATK buff from Mirror-BladeATK and DEF are boosted / Restores HP when 3 or more Mirror-Blades are deployed (Max: 5 / Can't be removed)
    .