Fionn mac Cumhaill is a boss in Shin Megami Tensei V (SMT 5). Read on to know the best strategies to use against Fionn mac Cumhaill, Fionn mac Cumhaill's weaknesses, best demons to use against Fionn mac Cumhaill, the best buffs to use to counter Fionn mac Cumhaill, and the most effective strategies to use to beat Fionn mac Cumhaill!
| Fionn mac Cumhaill Guides | ||
|---|---|---|
| Boss Guide (1st Fight) | Boss Guide (2nd Fight) | Stats and Fusion Guide |
List of Contents
 Find the Quest Location in TaitoUse Electric AttacksNull Physical and Ice DamageUse Fire Dampeners on Magatsuhi ChargeUse Buffs and Debuffs |
 |
||
| Recommended Level | Location | Drops |
|---|---|---|
| 66 | Taito | None |
You can find Fionn's quest in Taito the location above after completing all quests in the Fairy Village in Shinagawa. Once you talk to him and accept the quest, the boss fight will begin immediately, so be sure to save before speaking to Fionn.
Use Electric skills like Ziodyne to hit Fionn's weakpoint to extend your turn and deal the most damage to this boss.
Fionn mac Cumhaill has access to three damage types: Physical, Fire, and Ice. Primarily you will want to have protection from Physical and Ice moves as the boss' Maragidyne is only ever used after charging Magatsuhi. By nulling Physical and Ice damage, you will ensure that you have protection against all of Fionn's regular attacks.
For practicality, only focusing on nulling Physical damage should be enough as long as no demons on your team are weak to Ice-damage.
Since it Maragidyne is only ever cast as a Magatsuhi skill, use this to your advantage and use a Fire Dampener any time Fionn mac Cumhaill charges Magatsuhi. This will burn the bosses turn allowing you to get more damage in.
Fionn mac Cumhaill has no way of negating buffs to your party, although he has a buff of his own, Tarukaja, to raise his attack. Using both buffs and debuffs in this fight is highly recommended to make this boss more manageable.
| Girimehkala | Thor | Loup-garou |
| Siegfried | Dominion | Loki |
| Ishtar | Cleopatra |
Ishtar naturally has access to Ziodyne and her base fusion level is 62, which is pretty close to the recommended level of 66 for this boss fight. Also, her affinities are neutral toward Physical, Ice, and Fire, so you don't need to worry about Ishtar getting hit with an elemental weakness.
Girimehkala is a great choice for this fight as most of Fionn mac Cumhaill's attacks are Physical, and Girimehkala repels physical damage. Not only that, but Girimehkala's base fusion level is 66 which is exactly the recommended level for this boss, plus Girimehkala isn't weak to Fire or Ice damage either, making him a very useful party member in this fight.
If you have access to the DLC, Cleopatra's Frolic is a very effective debuff. Also if Cleopatra already knows Luster Candy you can really gain the advantage quicklly against this boss.
| Strength | 63 |
|---|---|
| Vitality | 46 |
| Magic | 58 |
| Agility | 42 |
| Luck | 44 |
| Physical | Fire | Ice | Electric | Force | Light | Dark |
|---|---|---|---|---|---|---|
| - | Null | - | Weak | - | Null | - |
| Sleep | Confuse | Charm | Mirage | Seal | Poison |
|---|---|---|---|---|---|
| Null | Resist | Resist | Resist | Null | Resist |
| Physical | Fire | Ice | Electric | Force | Light | Dark |
|---|---|---|---|---|---|---|
| ＋５ | ＋４ | ＋３ | −６ | - | - | - |
| Almighty | Status Ailment | Recovery | Support |
|---|---|---|---|
| - | - | - | - |
| Skill | Description |
|---|---|
| Mac an Luin | Severe Physical attack to 1 foe. Greater effect if a Critical hit. |
| Mist Rush | 2-4 medium Physical attacks to random foes. Chance of inflicting Mirage. |
| Pierce Armor | Weak Physical attack to 1 foe. Lowers target's Defense by 1 rank for 3 turns. |
| Bufudyne | Heavy Ice attack to 1 foe. |
| Maragidyne | Heavy Fire attack to all foes. Only used as a Magatsuhi Attack |
| Tarukaja | Raises Attack of 1 ally by 1 rank for 3 turns. |
| Fatal Sword | Medium Physical attack to 1 foe. High chance of Critical. |
| Deathbound | Medium Physical attack to all foes. |
| Omagatoki: Critical | Magatsuhi Skill: All attacks, including magical attacks, will become Critical hits for all allies for 1 turn. |
Boss Battle Guides | List of Bosses
| Related Boss Guides | |
|---|---|
 Story Bosses |
 Optional Bosses |
 DLC Bosses |
|
| Optional Boss Guides | |
|---|---|
 Pazuzu |
 Anahita |
 King Frost |
 Thunderbird |
 Loki |
 Belphegor |
 Moloch |
 Amanozako |
 Camael |
 Abaddon |
 Arahabaki |
 Khonsu |
| Fionn mac Cumhaill (2nd Fight) |
 Baal |
 Huang Long |
 Asura and Mithras |
 Amon |
 Gabriel, Raphael, and Uriel |
 Belial |
 Michael |
 Inanna |
 Danu |
 Maria |
 Khonsu Ra |
 Zeus (2nd Fight) |
 Shiva |
| Optional Boss Guides | |
|---|---|
 Apsaras |
 Leanan Sidhe |
 Shiki-Ouji |
 Xuanwu |
 Jatayu |
 Kumbhanda |
 Quetzalcoatl |
 Baihu |
 The Kunitsukami |
 Futsunushi |
 Adramelech |
 Zaou-Gongen |
| Punishing Foes Guides | |
|---|---|
 Oyamatsumi |
 Horus |
 Girimekhala |
 Hecatoncheires |
 Chimera |
 Seth |
 Bishamonten |
 Jikokuten |
 Koumokuten |
 Zouchouten |
 Garuda |
|
| DLC Boss Guides | |
|---|---|
 Artemis |
 Cleopatra |
 Mephisto |
 Matador |
 Daisoujou |
 Hell Biker |
 White Rider |
 Red Rider |
 Black Rider |
 Pale Rider |
 Mother Harlot |
 Trumpeter |
 Demi-Fiend |
|
How to Beat Fionn mac Cumhaill (2nd Fight)
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