Astraea

"I am the arbiter goddess. No matter who you are, when these scales tip, I must pass judgment!" 

The eternally haughty Luvia Edelfelt appears as a Pseudo-Servant for Astraea, the Greek goddess of Justice. Astraea is both the first non-limited SR Ruler and the first Ruler with an offensive Arts NP. She excels in her role as a critical-focused Arts servant, sporting multiple sources of instant star generation, an excellent star gathering and critical damage skill, and Independent Action.

Astraea functions primarily as a selfish point Servant for Arts Critical teams, and in that role she needs relatively little help in order to operate at full strength. With her innate critical tools, her stacking NP steroids, and her common anti-trait NP bonus, Astraea’s damage potential is excellent. Additionally, she has good NP refund potential and a versatile targeted buff skill, along with the innate defensive advantage inherent to her Ruler class.

As a Ruler, however, Astraea will only rarely have offensive class advantage, which puts her at a disadvantage as a damage-dealer relative to Knight- and Cavalry-class Servants. She also has no way to withstand enemy NPs without help, as she has no evasion or invulnerability skill to carry her through a high-damage turn. While her Arts card NP gain is respectable relative to her deck and her Arts cards benefit from Territory Creation, her lackluster Quick and Buster cards mean her performance will drop significantly while her skills are on cooldown.

All in all, Astraea’s general lack of offensive class advantage means she is unlikely to be the best choice to bring to any given fight. She will, however, almost always be at least a good choice, and her self-sufficiency will make her particularly valuable for Masters without native access to the high-tier supports.

Reliable Critical Access

Astraea generates 20 stars each time she uses her NP and can make another 30 on-demand with the help of her Mana Burst (Star). With her short-cooldown star absorption skill thrown into the mix, she’ll have no trouble critting even without star support. With good damage boosts all-around, she’s among the most self-sufficient critical-based Servants in the game.

Strong NP Loop Potential

Astraea’s base NP gain is nothing exciting -- and her Quick card is quite weak -- but with her NP gain buff active and Territory Creation factored in, her Arts card NP gain becomes much more impressive. Her Mana Burst can push her NP gain even higher for a turn, and her easy access to crits helps to ensure she maximizes this NP gain potential. With favorable card draws, Astraea will have no trouble using her NP twice in succession, and proper support can enable sustained looping.

Ruler Class Bulk

As a Ruler, Astraea takes half damage from most enemies. She also has a modest defense buff that will likely be active more turns than not, so while she has no self-healing or hard survivability, she shouldn’t have much trouble withstanding enemy cards.

Swap-In Star Support Potential

While Astraea is primarily meant as a damage-dealer, her ability to produce 30 stars on-demand and to give a general-performance boost to an ally gives her potential to be used as an alternative to Mozart. In particular, the Chaldea Combat Uniform’s Order Change ability can allow Astraea to swap-in and provide a burst of support on an important turn.

Lack of Offensive Class Advantage

While Astraea has an excellent damage-dealing kit, she hits most targets for neutral and as such will likely be outdamaged by Servants with class advantage. For Masters with well-developed Servant rosters, this will likely limit Astraea’s appeal.

Lack of Hard Survival

Astraea withstands normal cards well, but her lack of an Evasion or Invincibility skill means she’s susceptible to enemy NPs without the help of supports. This is fairly easy to work around in most cases, but it stands out against what is otherwise a remarkably self-sufficient kit.

Weak Quick and Buster Cards

The lower hit-counts on Astraea’s Quick and Buster cards make them much less appealing than her Arts cards. Her in-kit buffs also skew in the direction of Arts, so Astraea’s performance is likely to dip somewhat if she doesn’t draw her Arts cards at the right time.

All three of Astraea’s skills are comparably useful, and she really wants all three to be leveled evenly. All three skills benefit significantly from reaching max level, as their relatively short cooldown timers mean Astraea has little downtime in her damage-dealing capability.

• Blessing of the Scale A+ is a general-purpose performance boost, providing modest buffs to the target’s Attack, Defense, and NP gain for three turns. While this skill is targetable, Masters are likely going to want to use this on Astraea most of the time, as it solidifies her NP gain and strengthens her NP and her crits. Supports and semi-supports with good NP gain (for example, Sherlock Holmes or Qin Shi Huang Di) may benefit from the effects as well, though, allowing for greater flexibility on Astraea’s part.
• Mana Burst (Star) A is a weak Mana Burst from a strictly damage-oriented perspective, giving a maximum boost of 30% where most one-turn card-type buffs give 50%. In exchange, though, it also doubles as a powerful source of on-demand Critical Stars, giving a whopping 30 stars on use. With passive star generation (such as from Merlin, Hans, or 2030), this will likely bring the whole party’s crit rate to nearly 100%, and even without passive star gen it pairs nicely with Astraea’s third skill to enable crits for Astraea herself.
• Star's Judgment A is an extraordinarily powerful skill that combines Star Absorption and Critical Damage effects on a short cooldown. This would be strong on its own, but it also gains a small NP charge effect, meaning this skill enables both Astraea’s critical damage and her NP spam potential. The 5-star demerit is a small price to pay for this combination of effects, especially considering Astraea tends to make plenty of stars on her own. The only real drawback here (if it can even be considered a drawback) is that this has obvious synergy with Astraea’s Mana Burst despite being on a shorter cooldown, so if Astraea’s team lacks an outside source of stars, the fast cooldown may be slightly wasted.

Astraea is mostly set as far as crit shenanigans go already, so she’ll benefit most from CEs that strengthen and enable her NP while her Mana Burst is on cooldown. Arts Performance Up is the simplest answer here, boosting her NP damage, Arts Criticals, and effective NP gain. NP Gain Up can be valuable if Masters want to prioritize using Astraea’s NP as frequently as possible. Lastly, NP Damage Up stacks multiplicatively with everything in Astraea’s kit, ensuring she’ll do maximum damage any time she uses her NP.

• Formal Craft / Another Ending / Projection: Arts Performance boosts are the most straightforward way to lift up Astraea’s effectiveness. Another Ending is particularly noteworthy given Astraea’s reliable critical access, although the larger Arts boost from Formal Craft may still be preferable.  
• Painting Summer / Magical Girl of Sapphire / Divine Banquet: Painting Summer is an absolutely phenomenal CE for pretty much any Arts damage-dealer, pairing a 50% starting NP effect with both Arts up and NP gain up. Magical Girl of Sapphire fills a similar role, trading some damage for slightly faster effective NP gain. Divine Banquet is a weaker but more accessible option.
• Sign of Smiling Face / The Black Grail / Afternoon in the Citadel: Sign of Smiling Face is possibly a better pick for Astraea than Painting Summer is, dropping the starting NP (which Astraea doesn’t particularly need anyway) in favor of an NP damage boost. The Black Grail is always a massive damage increase for NP-centric Servants. Afternoon in the Citadel provides a hefty boost to Astraea’s NP damage and a solid boost to her Buster and Arts cards as well. Afternoon is occasionally maligned for its full-HP stat spread, but due to her class Astraea effectively doubles that additional HP pool, meaning she benefits from the bulky stat spread more than most servants do.
• GUDAGUDA Poster Girl / Golden Captures the Carp: GUDAGUDA Poster Girl allows Astraea to swap in, support an ally, draw enemy attacks, and then leave the field to make way for a longer-term support. Astraea can also leverage the CE’s three-turn Attack boost for powerful critical attacks before she dies. Golden Captures the Carp pairs with Mana Burst (Star) to allow Astraea to produce 50 stars on her swap-in turn for guaranteed critical hits.