Cu Chulainn (Prototype)

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April Fool's
Lawful Balanced
Max HP 10,098
HP Rank
Max ATK 7,082
ATK Rank
Base Atk1,315Base HP1,817
Max Atk 7,082 Max HP 10,098
Grail Atk 9,584 Grail HP 13,691
NP per Hit (%) 1.08%
NP when Attacked (%) 4%
Star Absorption 88
Star Generation per Hit 12.1%

Table of Contents

Servant Skills

Rune Spell B

Increases own critical damage for 3 turns.
Increases own debuff resistance for 3 turns.

Show Info
Crit Damage + 18%20.7%23.4%26.1%28.8%31.5%34.2%36.9%39.6%45%
Debuff Res + 18%20.7%23.4%26.1%28.8%31.5%34.2%36.9%39.6%45%
CD 7 7 7 7 7 6 6 6 6 5

Available from the start

Protection from Arrows B

Grants self Evasion for 3 attacks.
Increases own defense for 3 turns.

Show Info
Defense + 8%8.8%9.6%10.4%11.2%12%12.8%13.6%14.4%16%
CD 7 7 7 7 7 6 6 6 6 5

Unlocks after 1st Ascension

Beast-Slayer B+

Increases own attack against Beast enemies for 3 turns.

Show Info
Attack + 40%42%44%46%48%50%52%54%56%60%
CD 7 7 7 7 7 6 6 6 6 5

Unlocks after 3rd Ascension

Beast-Slayer B++

Increases own attack against Beast enemies for 3 turns.
Increases own critical star absorption for 3 turns.

Show Info
Attack + 50%55%60%65%70%75%80%85%90%100%
Stars Absorption + 200%230%260%290%320%350%380%410%440%500%
CD 7 7 7 7 7 6 6 6 6 5

Upgrades after Rank Up Quest

Class Skills

Magic Resistance C

Increase your Debuff Resist by 15%.

Divinity B

Apply Damage Plus for yourself (Total Card Damage +175).

Noble Phantasm

Gae Bolg (Prototype) B

Deal significant damage to a single enemy.


Decrease DEF for a single enemy (3 turns).
Medium chance to inflict Death.

Show Info

Gae Bolg (Prototype)

Barbed Spear that Pierces with Death

Rank Classification Hit-Count
B Anti-Personnel 1

Deal significant damage to a single enemy.

Level 1 2 3 4 5
1200% 1600% 1800% 1900% 2000%
Overcharge Effect

Decrease DEF for a single enemy (3 turns).
Medium chance to inflict Death.

Charge 100% 200% 300% 400% 500%
10% 15% 20% 25% 30%
50% 62.5% 75% 87.5% 100%

Assorted Info

ID 20
Cost 7
Gender Male
Growth S
Inst. Death Chance 28.00%
Damage Distribution Quick 33,67
Damage Distribution Arts 33,67
Damage Distribution Buster 100
Damage Distribution Extra 12,25,63
Damage Distribution NP 100

Attack / HP Growth

Stat Ratings

Interlude Quests

Quest Requirements Reward
Chapter Completion: Fuyuki

Ascension: 1

Bond: 2

Rank Up 1
Chapter Completion: Chaldea Gate

Ascension: 4

Bond: 0

✔ = Available ✖ = Unavailable

Ascension Materials


Skill Enhancement Materials

1 → 2 50,000
2 → 3 100,000
3 → 4 300,000
4 → 5 400,000
5 → 6 1,000,000
6 → 7 1,250,000
7 → 8 2,500,000
8 → 9 3,000,000
9 → 10 5,000,000

Costume Dress Materials

Costume Cost Materials
April Fool's

Bond CE

Bond Level 1 2 3 4 5 6 7 8 9 10
Bond Pts Req. 2,000 3,000 4,000 5,000 6,000 190,000 208,000 252,000 310,000 360,000
Hound of Culann

When equipped to Cu Chulainn (Prototype) only,
All allies will inflict 20% bonus damage against [Wild Beast] enemies while on the field.

Table of Contents


Proto Cu is, in essential, a much more offensive version of normal Cu Chulainn. Trading Battle Continuation and Disengage for the ability to do critical damage reliably and increased damage against Beast type enemies allow him to serve as a great budget damage dealing Lancer. Beast-trait is a quite common trait amongst frequently appeared enemies, such as Chimera, meaning Proto Cu will prove quite useful for these type of enemies and will only become more valuable as the game goes on. And while he does not have Guts, Proto Cu is still extremely tanky thanks to Protection from Arrows and is more than adequate for him to find a place in tough challenges.

Proto Cu however is not without flaws, as he has a somewhat awkward deck of BBQQA which hampers his NP generation rate while does not really contribute much to his Star generation rate either. He also does not contribute much to the team in term of buffs or debuffs, and while he is a good Servant independently, he needs heavy support to reach his full potential.


  • Hard to kill thanks to having Protection from Arrows
  • Great damage potential for a 3 Star Servants thanks to possessing both a Critical Damage increase and Star Absorbtion buff
  • Is a great choice when battling enemies with Beast trait (a quite common trait that's often found in events/daily maps)


  • Awkward card deck for NP generation combined with fairly normal NP generation rate means he often need support to get to 100% NP bar
  • Lack of Attacks or Card Performance boost to improve his NP damage output and often rely on Critical Hits to deal meaningful damage, making him more dependent on team support
  • Mediocre Star generation capability despite having a light Quick deck due to low hit count on his cards

Level Up Skill Recommendation

Divine Protection from Arrows is the claim to fame for both Cu Chulainn and it is what gives them incredible tankiness for hard battles. Thus, you'd do a disservice not leveling it first.

Afterward, Beast Slayer is better than Rune Spell as it gives Cu Chulainn Prototype a unique niche against certain enemies. Furthermore, in the long run, it is also a great offensive skill after the Rank Up due to the crit stars absorption.

Rune Spell is his least important skill, not because it is bad, but because it isn't particularly good on him until he receives his crit star absorption component on his 3rd skill, so it should be leveled last.

Craft Essence Recommendation

Being a strong survivalist and critical damage dealer (once he gets his Rank Up quest), Cu Chulainn Proto appreciate any form of Quick card performance boost as well as a critical damage boost.

  • Imaginary Around / Gandr - the basic Quick card booster CEs are perfect for him as he has a light Quick deck (BBQQA)
  • Guda-O / Holy Night Sign: Craft Essences that give him two out of several stats that he want
  • Gem Magecraft: Antumbra / Knight's Dignity: For team that make Cu Proto the main Critical Damage Dealer

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Other Info

Release Date Since Launch
AKA/Alias/Nicknames Setanta, Proto Cu, Proto Lancer
Country/Place of Origin Ireland
Illustrator Nakahara
Seiyuu (CV) Kazuya Nakai
Series Fate/Prototype



Valentine's CE


Non-Limited - Available in the general summoning pool.

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