Isaac is a skill damage-focused character with high value of durability. Combination of his two damaging skills, one which can auto-activate and the other with 1100% damage multiplier, and his high-endurance ShieldNext ATK received will be ineffective for a fixed amount that doubles as ImmuneDebuffs will be nullified and caps Fire damage he receives, allows him to relentlessly assault foes with skills while staying high on health.
Strengths
Thermal Blade1100% Water damage to all foes (Damage cap: ~1,200,000). Inflict 25% ATK DownATK is lowered Strength: 25%Duration: 4 turnsLocal status effect and 25% DEF DownDEF is lowered Strength: 25%Duration: 4 turnsLocal status effect. is a massive nuke to all foes and debuffing skill stacked in one button, allowing skills like Miserable MistInflict 25% ATK DownATK is lowered Strength: 25%Base Accuracy: 80%Duration: 180 secondsStacking: Dual and 25% DEF DownDEF is lowered Strength: 25%Base Accuracy: 80%Duration: 180 secondsStacking: Dual on all foes. to reach ATK/DEF Down cap.
Plasma Ripper500% Water damage to all foes (Damage cap: ~635,000). Gain Charge Bar +20%Instantly boosts Charge Bar by 20% Strength: 20%. doubles as a skill that rapidly fills his charge bar, allowing him to deal charge attack faster, besides damaging multiple foes.
The skill automatically activates after normal attacks thanks to Motor Drive50% hit to double attack rate and 50% hit to triple attack rate. AmplifyMultiplier:Seraphic normal attack damage by 30%. Activate Plasma Ripper500% Water damage to all foes (Damage cap: ~635,000). Gain Charge Bar +20%Instantly boosts Charge Bar by 20% Strength: 20%. after normal attacks..
Motor Drive50% hit to double attack rate and 50% hit to triple attack rate. AmplifyMultiplier:Seraphic normal attack damage by 30%. Activate Plasma Ripper500% Water damage to all foes (Damage cap: ~635,000). Gain Charge Bar +20%Instantly boosts Charge Bar by 20% Strength: 20%. after normal attacks. amplifies damage he deals with normal attacks.
He can easily deal massive burst damage in short amount of turns with Rocket ThrusterGain Instant ChargeInstantly sets Charge Bar to 100% Unaffected by Charge Bar Gain status effects. No effect when afflicted with Shorted debuffs or when Charge Bar is above 100%. and Charge BoostCharge bar will be boosted to 100% at the end of the turn Duration: 2 turns., granting him Instant ChargeInstantly sets Charge Bar to 100% Unaffected by Charge Bar Gain status effects. No effect when afflicted with Shorted debuffs or when Charge Bar is above 100%. and Charge BoostCharge bar will be boosted to 100% at the end of the turn .
For every charge attack he deal, Thermal Blade1100% Water damage to all foes (Damage cap: ~1,200,000). Inflict 25% ATK DownATK is lowered Strength: 25%Duration: 4 turnsLocal status effect and 25% DEF DownDEF is lowered Strength: 25%Duration: 4 turnsLocal status effect. resets its cooldown, which ensures him to deal burst damage in short turns.
Extravehicular GearStarts battle with Shield (6000)Next ATK received will be ineffective for a fixed amount Strength: 6000Duration: Indefinite. When Isaac has ShieldNext ATK received will be ineffective for a fixed amount : Debuff immunity and caps incoming Fire damage at 5000 per hit. protects him with preemptive Shield (6000)Next ATK received will be ineffective for a fixed amount Strength: 6000. It grants Isaac ImmuneDebuffs will be nullified and caps Fire damage at 5000 per hit, as long as his shield lasts.
He can also regain the shield with his own charge attack.
Works best against multiple enemies, where he can fully make use of his all-foe damaging skills.
Weaknesses
His debuffs are local status effects. Even with their high values, the debuffs only benefits the caster's party, not the others.
ShieldNext ATK received will be ineffective for a fixed amount gained from Extravehicular GearStarts battle with Shield (6000)Next ATK received will be ineffective for a fixed amount Strength: 6000Duration: Indefinite. When Isaac has ShieldNext ATK received will be ineffective for a fixed amount : Debuff immunity and caps incoming Fire damage at 5000 per hit. and charge attack can be dispelled, which hurts his survivability against enemies able to dispel character buffs.
How to Play
Synergy
Skill Damage Cap Up
As a lot of his damage comes from skills, Isaac greatly appreciates any sources of skill damage cap up. Some notable sources are:
Filene:Silvery SnowAll Water allies gain Silvery SnowWater ATK is boosted / Skill DMG is boosted / Maximum amount of skill DMG that can be dealt per hit is boosted (Can't be removed) Duration: 6 turns.
Macula Marius:Frigid MaidenBoost to Water allies' skill specs based on their number of Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) . (Takes effect even when Macula Marius is a sub ally.) (Note the Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) requirement.)
With his low multiattack rate down to negative value, it's practically impossible for him to deal multiattacks consistently. Guaranteed DAGuaranteed double attack regardless of Double Attack Lowered debuffs and Guaranteed TAGuaranteed triple attack regardless of Triple Attack Lowered debuffs are bypassing his inability to do so, thus exploiting his already strong normal attacks. Some notable sources of guaranteed multiattacks are:
Dancer:Classical LeadGain EtoileAllies positioned after you will copy your attack Duration: 1 turn . (Requires MC to deal multiattacks.)
Masquerade:Bounce ChasseAll allies gain Guaranteed TAGuaranteed triple attack regardless of Triple Attack Lowered debuffs Duration: 1 turn and Double StrikeAttacks twice each turn Duration: 1 turn . Inflict C.A. SealedCan't use charge attack Duration: 1 turn on all allies. (Consumes 10 PromenadeMultiattack rate is boosted based on Promenade lvl (Can't be removed) lvls from all allies.)
Isaac will have issues gaining PromenadeMultiattack rate is boosted based on Promenade lvl (Can't be removed) lvls due to his non-existing multiattack rate, but this can be partially negated by taking Non-Sequence6-hit, 80% elemental damage to random foes (Damage cap: ~60,000 per hit). Raise all allies' PromenadeMultiattack rate is boosted based on Promenade lvl (Can't be removed) Duration: Indefinite lvl by 1. (Increase number of hits based on caster's PromenadeMultiattack rate is boosted based on Promenade lvl (Can't be removed) lvl [Max: 16 hits].).
Masquerade, being an Extra II class, has access to Dancer's Classical LeadGain EtoileAllies positioned after you will copy your attack Duration: 1 turn . while possessing improved support skills and ability to choose 3 free skills rather than 1.
Europa (Summer):Tyros BenedictusGain Guaranteed TAGuaranteed triple attack regardless of Triple Attack Lowered debuffs Duration: 1 turn and 15% DMG Cap UpMaximum amount of DMG that can be dealt per hit is boosted Strength: 15%Duration: 3 turns. (When Starry WatersATK is boosted / House of Thebes's hit number is increased (Max: 5 / Can't be removed) is at 5: Affects all allies.) (Requires 5 Starry WatersATK is boosted / House of Thebes's hit number is increased (Max: 5 / Can't be removed) stacks to affect all allies.)
Grea (Summer):DragonheartGain DracostrikeTriple attack rate is boosted / Attacks made with elemental superiority have a chance to deal boosted DMG / Supplemental DMG to critical hits Duration: 2 turns. (Grants the same effect to an ally with LinkageGains Grea's skill and support skill effects (Can't be removed) .) (Blazing DuoGrant LinkageGains Grea's skill and support skill effects (Can't be removed) Duration: Indefinite to caster and an ally. (Can't grant LinkageGains Grea's skill and support skill effects (Can't be removed) Duration: Indefinite to more than 1 other ally at a time.) must be targeted to Isaac first.)
Lucio (Summer):Without YouGrant a Water ally 90% Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks Strength: 90%Duration: 2 turns, Guaranteed TAGuaranteed triple attack regardless of Triple Attack Lowered debuffs Duration: 2 turns, 70% Fire CutFire DMG is cut 70% Duration: 2 turnsFire Damage Cut., and 100% Debuff Res. UpDebuff resistance is boosted Strength: 100%Duration: 2 turns.
Bonus Damage
Without any source of guaranteed multiattack buffs, Bonus DMGDeals bonus DMG for one-foe one-ally attacks can be used instead to make use of his strong normal attacks. Although, they're still best combined with Guaranteed DAGuaranteed double attack regardless of Double Attack Lowered debuffs /Guaranteed TAGuaranteed triple attack regardless of Triple Attack Lowered debuffs for even better results. Some notable sources of bonus damage are:
Cagliostro (Summer):Ars NovaArs Nova: All Water allies gain 70% / 30% Critical Hit Rate UpAttacks made with elemental superiority have a chance to deal boosted DMG Strength: 70% chance of dealing 30% more damage.Duration: 3 turns, KeenSupplemental DMG to critical hits Strength: 1% of foe's max HP (Damage cap: 50,000)Duration: 3 turns, and 1 Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) Duration: Indefinite. (When Cagliostro's Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) Duration: Indefinite is 5: Skill changes to Ars Notoria.) Ars Notoria: All Water allies gain 100% / 30% Critical Hit Rate UpAttacks made with elemental superiority have a chance to deal boosted DMG Strength: 100% chance of dealing 30% more damage.Duration: 3 turns, KeenSupplemental DMG to critical hits Strength: 1% of foe's max HP (Damage cap: 50,000)Duration: 3 turns, 50% Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks Strength: 50%Duration: 3 turns, and 15% DMG Cap UpMaximum amount of DMG that can be dealt per hit is boosted Strength: 15%Duration: 3 turns. (Consumes 5 Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) stack from Cagliostro to grant Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks .)
Fateless (4★/Main):Frigid StingMassive Water damage to a foe. Remove 1 buff. Additional effect at 4★: All allies also gain 15% Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks Strength: 15%Duration: 3.5 turnsApplied during the attack phase. On the next turn, it'll have 3 turns remaining..
Juliet (Water):Fulmine AzzurroAll Water allies gain 1 Deluge CrestWater magic is amplified (Max: 5 / Can't be removed) Duration: Indefinite, Mirror Image (1 time)Next one-to-one attack received will be ineffective (Effect removed on next all-foe all-ally attack) Duration: Indefinite, and 20% Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks (Ends upon taking DMG) Strength: 20%Duration: Indefinite. (Bonus Water DMG effect ends upon taking damage.) (Ends upon taking damage.)
Societte:First Dance: KaguraRestore 30% of all allies' HP (Healing cap: 2000). All allies gain RevitalizeRecover HP each turn. Boost to charge bar if HP is full. Strength: 500 HP or 10% charge barDuration: 3 turns and 10% Bonus Water DMGDeals bonus water DMG for one-foe one-ally attacks Strength: 10%Duration: 3 turns. (When a foe uses a special attack: Consumes Yonagi RiteFirst Dance: Kagura activates when a foe uses a special attack (Can't be removed) to auto-activate.)
As a skill damage-focused character, taking two 3★ on Skill DMG Cap is a top priority. Round his damaging performance with 3★ on Critical Hit. The rest of unused points can be spent liberally, preferably DEF to ensure his ShieldNext ATK received will be ineffective for a fixed amount to last longer.
