Rabbit’s Reviews #397: Xu Fu (4* Avenger)

Introduction

Xu Fu is our first ST Buster Avenger at the SR level, and the only one we’ve gotten at all outside of Jalter. Overall, she’s pretty good! She has a bit of potential party utility, but mostly she’s just a strong anti-Man ST unit. She’s a Koyan-compatible Buster looper with solid base steroids and some good niche damage potential. She doesn’t really do anything notable outside of damage, but if you’re missing a strong ST Buster unit, Xu Fu can certainly fill that gap.

Servant Data

Avenger

QAABB (Saber)

Quick Card

Arts Card

Buster Card

4

5

9

Attribute	Human
Alignment	Chaotic Balanced

Stage 1
Stage 2
Stage 3
Stage 4

Max HP 11,000

HP Rank

Max ATK 9,686

ATK Rank

Base Atk	1,614	Base HP	1,760
Max Atk	9,686	Max HP	11,000
Grail Atk	11,728	Grail HP	13,337

Traits

Avenger (Pretense) B+

Decrease Debuff Resist for all allies except self by 9% [Demerit].
Increase own NP Gain when taking damage by 19%.

Oblivion Correction EX

Increase your Critical Strength by 12%.

High Servant -

No Effect

Weak Constitution (Yu Mei-ren) EX

Decrease own ATK against [Yu Mei-ren] enemies by 20%. [Demerit]

Card Hits	4	5	5	5	9
Per Hit	0.43%	0.43%	0.43%	0.43%	0.43%

	NP per Hit (%)						0.43%
	NP when Attacked (%)						5%

	Star Absorption	30
	Star Generation per Hit	5.8%

Overview

Xu Fu has the lowest attack and the highest health of the SR Avengers. Avengers are attack-oriented in general, so this still leaves her with pretty average stats relative to SRs as a whole. The Avenger class base means this isn’t a death sentence for Xu Fu, but it’s a bit disappointing that she doesn’t get to make full use of Avengers’ innate strengths. Xu Fu’s Arts card NP gain, meanwhile, is much better than is typical for her deck, which is unusual on an Avenger. Unfortunately, her Quick card NP gain is really weak. She’s also a single-Quick Servnat, but she has high hit-counts overall, though, so if you can give her a star gen buff she can generate a few stars off her cards.

Xu Fu’s passives are pretty restrained as Extra class Servants go. She has a unique version of Avenger, but it has the same effects as usual—extra defensive NP gain in exchange for making the party more susceptible to debuffs. Oblivion Correction, meanwhile, increases Xu Fu’s crit damage a bit. This is actually her only innate crit damage buff, though her power mod effects fall into the same bracket. High Servant does nothing, and because she is Xu Fu, Xu Fu has an innate attack reduction against Yu Mei-ren.

Xu Fu makes very good use of both Mana Loading and Skill Reload. Xu Fu is a 30% charger, so Mana Loading lets her loop with a 50% charge CE and a Koyan/Koyan/Oberon team, even without cards—and it means looping with something like Black Grail only takes a card or two. Skill Reload, meanwhile, lets Xu Fu reuse her various skills on turn 2 instead of turn 3, substantially increasing her turn 2 damage. Skill Reload also makes CE-less looping slightly easier, as one of Xu Fu’s skills grants passive NP gain. Aside from that, Xu Fu’s low in-kit crit buffs make the crit damage append a bit more appealing than usual, but aside from that there’s nothing really out of the ordinary about the others.

Material Requirements

Stage	Cost	Materials
2	50,000	x8 Fool's Chain x8 Ghost Lantern
3	150,000	x8 Forbidden Page x8 Shell of Reminiscence
4	500,000	x8 Mystic Spinal Fluid x8 Deadly Poisonous Needle
Max	1,500,000	x8 Ceremonial Sword of Twilight x8 Flaming Oni Lantern Plant

Level	Cost	Materials
1 → 2	100,000	x8 Fool's Chain
2 → 3	200,000	x8 Forbidden Page
3 → 4	600,000	x10 Mystic Spinal Fluid
4 → 5	800,000	x10 Mysterious Divine Wine
5 → 6	2,000,000	x10 Refined Magatama
6 → 7	2,500,000	x12 Soundless Bell
7 → 8	5,000,000	x12 Small Bell of Absolution
8 → 9	6,000,000	x12 Ceremonial Sword of Twilight
9 → 10	10,000,000	x1 Crystallized Lore

Level	Cost	Materials
1 → 2	100000	x8 Evil Bone
2 → 3	200000	x8 Ghost Lantern
3 → 4	600000	x10 Homunculus Baby
4 → 5	800000	x10 Eternal Ice
5 → 6	2000000	x10 Deadly Poisonous Needle
6 → 7	2500000	x12 Arrowhead of Malice
7 → 8	5000000	x12 Flaming Oni Lantern Plant
8 → 9	6000000	x12 Ash of Remembrance
9 → 10	10000000	x1 Crystallized Lore

Servant Skills

Xu Fu has a strong DPS-oriented skillset, and while there are a few unique elements in it, overall it serves just to facilitate looping and boost her damage. Recommended skill order is 1>3>2.

Arts/Buster Up

Taoist Technique (Doll Manipulation) A+

Increase own Arts Card effectiveness (3 turns).
Increase own Buster Card effectiveness (3 turns).
Increase own NP Gauge.

Show Info

Lvl	1	2	3	4	5	6	7	8	9	10
Arts +	20%	21%	22%	23%	24%	25%	26%	27%	28%	30%
Buster +	20%	21%	22%	23%	24%	25%	26%	27%	28%	30%
NP +	20%	21%	22%	23%	24%	25%	26%	27%	28%	30%
CD	8	8	8	8	8	7	7	7	7	6

Taoist Technique is a super straightforward skill, providing 30% Arts and Buster up, as well as a 30% battery. 30% charge is the minimum for a Buster unit to loop cardless with starting charge in a Koyan team, and if you factor cards in (which you usually should, for ST), it’s still convenient in terms of not wasting battery on turn 1 with Mana Loading. Since Xu Fu’s Arts NP gain is good, she even gets some decent use out of the Arts buff. There’s not much to say about this skill, other than that it’s solid and very welcome.

Start Np

Territory Development (Village) B++

Increase NP Gauge for all allies by 10%.
Increase NP Gauge for all allies each turn (3 turns).
Increase NP Overcharge Level by 1 for all allies (1 time, 3 turns).

Show Info

Lvl	1	2	3	4	5	6	7	8	9	10
NP per turn +	5%	5.5%	6%	6.5%	7%	7.5%	8%	8.5%	9%	10%
CD	8	8	8	8	8	7	7	7	7	6

Territory Development is a nifty skill, giving an immediate 10% charge to the party, along with an extra 10% charge per turn. Because of this skill, there actually won’t be much difference for Xu Fu between a level 1 and 10 Mana Loading. If Xu Fu has her Skill Reload append, this skill is functionally 10% extra charge on turn 1, and 20% extra charge on turns 2 and 3. This makes it pretty easy for Xu Fu to loop, even when CE-less—Xu Fu only needs an extra 10% NP gain from cards in order to loop, which she can get with a single Arts or Buster card. The skill also increases the party’s overcharge level by 1, which is a little extra damage for Xu Fu against Man enemies while bursting. All of these effects are also great for Castoria stall teams, and particularly Merlin/Castoria teams. This is a cool skill overall, providing a lot of party charge over the course of three turns.

Death Chance Up

Death Collection A

Increase own Instant Death Success Rate (3 turns).
Increase own NP Strength (3 turns).
Apply 20% Special ATK [Poison] to self (3 turns).
Apply 20% Special ATK [Curse] to self (3 turns).
Apply 20% Special ATK [Burn] to self (3 turns).

Show Info

Lvl	1	2	3	4	5	6	7	8	9	10
Death Chance +	60%	66%	72%	78%	84%	90%	96%	102%	108%	120%
NP Damage +	20%	21%	22%	23%	24%	25%	26%	27%	28%	30%
CD	8	8	8	8	8	7	7	7	7	6

Death Collection is a great damage boost. It gives 30% NP damage up for three turns, which can stack with Koyan and is doubled by Oberon. On top of that, this skill gives a 20% power mod against each of Poison, Curse, and Burn. Xu Fu has no intrinsic way to apply those statuses, but command codes can help with that, and since the power mod effects can also stack with Koyan, Xu Fu can reach remarkably high levels of damage just within her own kit. Under ideal circumstances—you have DoT CCs on Xu Fu’s cards and draw all of them at convenient times—this can give Xu Fu a whopping 120% total power mod on turn 2 or 3 against anything that’s not debuff-immune. If your supports also have the relevant command codes, this becomes even more reliable. You may not want to install command codes onto Koyan and Oberon just to facilitate Xu Fu, but you can always swap the supports’ CCs out if you need something different, and neither support benefits overly much from other CCs anyway, so it’s worth considering. Aside from that, the skill also boosts Xu Fu’s instant death success rate, which does interface with a gimmick on her NP… but outside of very specific cases, instant-death isn’t usually reliable enough to be worth considering. This is a very strong skill even without the instant death buff, and Xu Fu doesn’t really pay anything for having that extra skill component, so it can safely be ignored.

Noble Phantasm

Death by Twilight, Chainsaw by Dusk B+

Deal damage to a single enemy.
80% Chance to inflict Death on an enemy.
If Death succeeds, Increase ATK by 20% for all allies (3 turns).

<Overcharge>

Deal supereffective damage to [Human Attribute] enemies.

Show Info/Video

Death by Twilight, Chainsaw by Dusk

Yuugure ni te Zessoku, Tasogare ni te Chainsaw

	Rank	Classification	Hit-Count
	B+	Anti-Personnel	9

Effect	Deal damage to a single enemy. 80% Chance to inflict Death on an enemy. If Death succeeds, Increase ATK by 20% for all allies (3 turns).

Level	1	2	3	4	5
Damage +	600%	800%	900%	950%	1000%
Death Chance +	80%	80%	80%	80%	80%
Atk +	20%	20%	20%	20%	20%

Overcharge Effect	Deal supereffective damage to [Human Attribute] enemies.

Charge	100%	200%	300%	400%	500%
Supereffective ATK +	150%	162.5%	175%	187.5%	200%

Xu Fu’s NP is extremely plain in practice. It’s an ST Buster NP with anti-Man supereffective damage. Supereffective damage on an ST NP is not super common and is really powerful, especially when it comes on a Servant who has good steroids and solid damage even without that niche. Man is a fantastic niche for an ST Buster unit, too, since Koyan gives anti-Man power mod. With both Koyan’s buffs and this supereffective damage bonus, Xu Fu does a ton of damage to Man enemies. It’s a bit of a shame she doesn’t have ramp—or, in fact, anything else at all—but honestly this niche is useful enough to carry the NP on its own, and Xu Fu has plenty going on in her skills already.

“But Rabbit,” you might be saying, “this NP does have ramp!” And, technically, you would be right. This NP has a chance of inflicting instant-kill, and if it succeeds, it grants 20% attack up to the whole party. This might be cool, but it suffers from several drawbacks. For one, instant-death is extremely unreliable. It almost never works against Servants, and even against non-Servant enemies, death rates are highly variable. Even worse, the instant-death effect triggers after damage. This is usually what you want from instant-death, so it doesn’t impact refund… but in Xu Fu’s case, this means the instant-death effect will never proc if Xu Fu’s NP kills the target through damage alone. In order for the attack buff to go off, Xu Fu has to not deal enough damage to kill, and then roll successfully on the IK proc. Most enemies with high enough IK rates for Xu Fu to kill them will also have low enough health that Xu Fu’s NP will drop them before the IK can activate. As such, the attack buff is only likely to proc if you’re using Xu Fu as a support for another character, you’re not feeding her any buffs, and you’re having her pick off incidental bronze or maybe silver mobs with unusually high HP.

…Suffice it to say you’ll almost never see this proc. But that’s fine! Xu Fu is already strong enough—as with most instant-death related effects, you can treat this as flavor and leave it at that.

Usage Tips

Xu Fu’s pretty simple to use. Ideally you run her in either a Koyan/Koyan/Oberon team for quick kills, or in a Castoria stall team for longer fights. I usually recommend Himiko/Castoria for Buster Servants—the extra hits of Solemn Defense thanks to Himiko’s NP, coupled with Himiko’s various other benefits, are really nice for stall reasons—but Merlin’s recent skill buff might push him back over the top. He now has sustained crit damage up, which used to be one of Himiko’s advantages, and he has more party charge and can protect the party more often. For Xu Fu in particular Merlin is a good pick, as Xu Fu herself can increase Castoria’s overcharge level, further reducing the need for Himiko.

While Xu Fu provides a good amount of party charge, she’s not otherwise very support-oriented, so I wouldn’t try to use her that way. She can be good in dual-core setups, though, with a strong NP of her own paired with the ability to prop up her teammates’ NP gain.

Xu Fu’s power drops substantially outside of optimal teams, but her party NP gain can at least be helpful for lower-end Buster teams. Especially with his most recent buff, Merlin is an appealing support for Xu Fu in general. Even if you have no strong native supports, you can run Mash and Xu Fu with a friend’s Merlin for a pretty strong, if slow, Buster team. If Xu Fu has Mana Loading, this team even brings enough charge to let Xu Fu NP on turn 1 with a non-charge CE!

Xu Fu has easy NP access and strong NP damage, so the Black Grail will almost always be her best CE option. If you don’t have Black Grail or want to lean into card damage, though, CEs like Limited/Zero Over or Victor of the Moon are solid options. Xu Fu is quite low on crit damage buffs and probably doesn’t want crit damage CCs, so crit damage CEs are better for Xu Fu than for most other Servants—though the Black Grail still reigns supreme.

Xu Fu wants burn, poison, and curse CCs, so she can use her own cards to proc her status-based power mod. You have a couple of choices for how to approach this: you can make it easy to remember which card has which status by putting one on her Busters, one on her Arts cards, and one on her Quick, or you can mix and match. If you take the mix and match approach, I’d recommend putting the same status on Xu Fu’s Arts and Quick cards, and the other two statuses on Xu Fu’s two Busters. This may be less intuitive than doing two CCs for two statuses and one CC for the other, but you’ll usually want to take Xu Fu’s Busters whenever they appear, so this lets you always prioritize Xu Fu’s Busters and know that you just need to slot in one of the other cards at some point in order to inflict all three statuses.

The disadvantage of going 3/1/1 instead of 2/2/1 is that you’re more likely to not get some of your statuses early, but in exchange you’re also less likely to need to pick worse cards in order to inflict them.

Grail Potential

Conclusion

Xu Fu is a conventionally strong Buster ST. She’ll do truly excellent damage to Man units, and she’s not bad outside of that if you set up her CCs properly. She doesn’t have anything in the way of crit tools, and aside from some party charge she doesn’t really have any utility, but if damage is what you need, she’s got plenty. Nothing wrong with that.

Rabbit's Arbitrary Ratings

Overall: 9/10
Single-Target DPS: 10/10
AoE DPS: N/A
Survivability: 2/10
Offensive Utility: 3/10
Defensive Utility: 3/10
Farming Usefulness: 3/10
Chainsaw Proficiency: 10/10