Fionn mac Cumhaill

“I see. So this is how I gain more power.”

Fionn used to have a reputation for being a really bad Servant, to the point where some would jokingly call him a Rare Prism. Fortunately, a set of well-placed buffs has brought Fionn back to a position of strength. While he’s not the best at rapid damage output, Fionn has a lot of defense and utility tools that can help his team survive for long periods of time, making him a good choice for difficult fights. He also has the potential to loop his Noble Phantasm with proper support, making him a good Archer-farming Servant once Altria Caster is available.

With all his buffs in play, Fionn’s primary claim to fame is his defensive value. Uninhibited Resplendence lets Fionn protect his entire party from single-target attacks for a turn, while Mac an Luin reduces the enemy team’s attack, keeping enemy damage under control. Fionn also has Clairvoyance (Beauty) to speed up the whole team by increasing the party’s Critical Star Drop Rate and NP Gain. Additionally, while Fionn’s normal attack NP gain is weak, his Noble Phantasm has strong NP gain, meaning he can use his NP multiple turns in a row under the right circumstances.

Fionn does have several notable weaknesses, however. As is typical of Servants with lots of utility tools, Fionn’s damage is quite low, as his only innate damage boost lasts just one turn. Fionn also has very low NP gain on his normal attacks, which means he will struggle to gain access to his NP without the help of support Servants. Furthermore, he has fairly long cooldowns, which means he has to wait for several turns after using his skills before he can benefit from them a second time.

Fionn has come a long way. Where he used to be one of the worst SR Servants in the game, Fionn now has a clear place as a defense-oriented Arts unit. What he lacks in damage, he makes up for in his ability to keep his team alive and moving. For difficult fights where survivability is the name of the game, Fionn is a strong damage-dealer.

Defensive Support

Fionn’s Target Focus and Evade combination is a powerful form of defensive support, as it allows Fionn to protect his whole team from single-target damage for a turn. This can allow Fionn to protect his team against either single-target Noble Phantasms or dangerous critical attacks, both of which can potentially end an otherwise-successful fight. Fionn’s NP also reduces enemy attack, providing a bit of additional protection.

Party Utility

Clairvoyance (Beauty) boosts the entire party’s Critical Star Drop Rate and NP Gain. Not only does this help Fionn himself gain access to his NP, but it also helps support Servants use their NPs more frequently, which is important for defense-oriented teams.

NP Loop Potential

Fionn’s NP gain on his NP is high enough that, with the help of supports, he can use his NP multiple times in a row. Altria Caster, in particular, makes Fionn a viable farming Servant, especially against Archer enemies.

Low Damage Output

While Fionn benefits from an NP Interlude, his only damage buff is both weak and short-lived. As a result, he may struggle to deal enough damage for Challenge Quests and farming, especially at lower NP levels.

Low Normal Attack NP Gain

Fionn’s normal attacks have unusually low NP gain. While Clairvoyance (Beauty) offsets this a little bit, Fionn still struggles to build his NP gauge without the help of NP charge skills and supports. He may have trouble building towards his first NP if he does not have a Starting NP Gauge CE.

Long Skill Cooldowns

Fionn’s skills have generally long cooldowns, especially relative to their effect durations. Fionn’s longest-lasting skill, Clairvoyance (Beauty), is active about half the time at max level, while his other skills are active 1 turn out of 7 and 1 turn out of 5. This means Fionn has to be careful with the timing of his skills, as he will have to wait several turns before he can benefit from the effects of his skills again.

Uninhibited Resplendence is Fionn’s best skill, serving as both a powerful survival tool and an NP charge skill. The dodge can fail at levels below 10, the NP charge effect scales with level, and cooldown times on defensive skills can be the difference between a win and a loss in a hard fight, all of which make this skill a high priority for leveling. Clairvoyance (Beauty) is a significant performance increase for Fionn and his allies and should be leveled second. Magecraft increases Fionn’s potential damage output, but the short duration makes it less appealing than Fionn’s other skills, so it can be saved for last. Masters planning to use Fionn primarily for difficult fights should take his first two skills to max level, but Magecraft can safely be left at lower levels. Masters planning to use Fionn for farming will need to max all three skills.

• Clairvoyance (Beauty) helps the entire team move faster. The Critical Star Drop Rate buff is relatively small, and Fionn himself will not benefit much from it given his low hit-counts, but this can allow high-hit-count support Servants to generate a fair number of stars, helping to fuel critical hits. The increased effective critical hit rate coupled with the skill’s NP gain boost will help the whole team NP more frequently.
• Uninhibited Resplendence draws enemy attacks to Fionn while also protecting him from those attacks. In difficult fights, this skill should be saved for turns where enemies are likely to use powerful critical attacks or single-target NPs. Taking enemy hits also makes it easier for Fionn to gain access to his Noble Phantasm, as he benefits from defensive NP gain on the attacks he takes. The skill also provides a flat NP charge, which makes this skill useful for farming.
• Magecraft is Fionn’s only damage buff. Arts buffs are especially good as card-type buffs go, as they increase both damage and effective NP gain. Unfortunately, this only lasts for a single turn, and the buff is weaker than most one-turn damage boosts, making this an underwhelming skill in practice.

Starting NP Gauge Craft Essences are particularly good for Fionn, as they both help him get moving more quickly in hard fights and make it easier for him to farm. NP Damage Up Craft Essences are good options for boosting Fionn’s damage output, especially once Altria Caster is available to help cover his NP charge and NP gain needs. Arts Performance Up Craft Essences, by contrast, strike a balance between increasing Fionn’s damage and facilitating his NP usage.

• Kaleidoscope / The Imaginary Element / Painting Summer: These CEs help Fionn gain access to his NP quickly. Kaleidoscope or an MLB The Imaginary Element can let Fionn use his NP right away with just his own skills, while Painting Summer provides additional useful buffs and only requires an additional 20% charge to do the same.
• The Black Grail / Heaven’s Feel: These CEs provide the largest increase to Fionn’s damage output. The Black Grail is particularly useful for farming with Altria Caster, as it can help Fionn overcome his damage issues.
• Formal Craft / Projection / Mark on a Smiling Face / Dive to Blue: These CE’s increase Fionn’s Arts Performance, increasing his damage and helping him to use his NP more frequently. These CEs can be a good choice for longer fights, especially if Fionn’s supports can help him reach his first NP quickly.