Hephaistion

“I'm nothing more than a counterfeit who borrowed her brother's name.”

Hephaistion in life was the most beloved of Alexander the Great’s friends, a boy who remained close throughout his entire life. Then we have Hephaistion of the FGO world, a female sorceress who serves as a Single Target Arts Damage Dealer who most certainly is not Hephaistion and hates him, making her a Pretender.

Hephaistion packs a solid kit meant to charge her Noble Phantasm and then dish out large amounts of damage to enemies. First of course is her massive charging ability through Rapid Words of the Divine B which can give her instantaneous access to a Noble Phantasm regardless of her gauge. Then we have her wide versatility thanks to Pretender classing as well as He Too Is Iskandar (False) A’s boost to give her full class advantage against Casters. She also can work pretty well in taking hits for the party with her third skill Nameless's Blessing EX.

The biggest issue surrounding Hephaistion is her lack of a hard damage negation. Further, her Caster class advantage is not permanent, meaning she may eventually struggle against more durable Caster bosses. She also can be quite squishy without supports.

Hephaistion is an excellent single target damage dealer against all enemies except Riders and Assassins. All Masters would be well served by the convenience of her full gauge change, and be especially well served if they have multiple Altria Casters to support. 

Charge Skill

Hephaistion has a charge skill of the Gods, giving her a full gauge whenever she wishes to use her Noble Phantasm, so long as it is leveled up to at least level 8. This enables her to use three Noble Phantasms with starting Gauge CEs and specific supports, or with two Castorias and an Oberon to support her.

Versatility

As a Pretender, Hephaistion already deals decent 1.5x class advantage damage against Sabers, Lancers, and Archers. Further, with her third append skill she can boost damage against Lancers to nearly the point of full class advantage. This advantage is supposed to be countered with disadvantages against Riders, Casters, and Assassins, but her first skill gives her full class advantage against Casters. With so few disadvantages, she can be used in nearly all ST situations. 

Taking Hits

Hephaistion’s third skill gives her a target focus with a defense up boost. While this could be helpful to take some hits from an enemy, it can also be used to negate an enemy’s Noble Phantasm if evade/invincibility can be provided to her by a support.

No Hard Damage Negation

As mentioned above, hard defense needs to be provided to Hephaistion by a support. She cannot give it to herself, meaning she has little to no means of protecting herself. 

Poor Sustain

In longer battles, Hephaistion will show crippling weaknesses. Her Caster advantage only lasts for three turns on a six-turn cooldown, meaning that if a battle goes for a while she will deal double damage for half the time, and half damage the other half. 

General Squishiness

Hephaistion has a hard time mitigating damage. While she has a 50% Defense boost for a turn, it is tied to taking all the hits for that turn with a target focus. Otherwise, she will take all damage which outside of Casters will be at full value. She may not last long without significant support.

Hephaistion’s kit highly revolves around her second skill and its ability to charge her gauge fully. Using this at a strategic time allows her to fire off a ton of Noble Phantasms against her enemies, boosted with damage from her first skill. Typically a master will use the first skill on turn one, the third skill either turns one or two for its NP gain boost, and then the second skill on the turn with the least gauge refunded. She will require careful planning, but a recommended leveling order is 2 > 1 > 3.

• He Too Is Iskandar (False) both acts as a way to boost up Arts and Buster damage, as well as a way to gain class advantage against Casters. Masters should cast this turn 1 to maximize her damage output. It can be left at level 9 if lacking in materials. Level this second.
• Rapid Words of the Divine B is a straight charge skill which can boost the gauge up to 120%! In most cases, this full amount is not needed, so this can be left at level 8 where she’ll still receive a full gauge. Level this first.
• Nameless's Blessing EX serves two functions. The first is a general tank move, taking all attention to herself and increasing her defense. This is helpful for enemy Noble Phantasm turns if she can be otherwise made invulnerable or can survive the oncoming damage. The second is a gain to her NP rate, allowing her to get a bit extra boost to her refund on a turn. It also absorbs curses from allies but that rarely sees application. This skill is useful for looping. Masters can leave this as the last skill, but should level it to max if looping with her to take full advantage of the NP gain.

Hephaistion primarily wants a CE which boosts her damage as much as possible, making Noble Phantasm Damage Up CEs particularly effective. Without one, she can benefit with a Mixed Damage / Starting Gauge Up CE which can allow for different refund scenarios with double Castoria.

• The Black Grail: As Hephaistion has the ability to fully charge herself, she can easily use a Black Grail to dish out a huge amount of damage on any turn of her choosing. Through supports she can actually use a Black Grail and dish out three Noble Phantasms in three turns as well. More damage is always the best. 
• Ocean Flier / Painting Summer / New Beginnings / Golden Sumo: Boulder Tournament / Holy Night Supper: The absolute best thing to do with Hephaistion if one does not have all the best supports is to give her a starting gauge of some sort, along with boosts to her NP gain rate. CEs which boost her Arts are the best for this. 
• Kaleidoscope / The Imaginary Element / Dragon’s Meridian: Lacking supports of any kind, it is best to get Hephaistion a starting gauge of some sort so she can fire her noble phantasm at least twice. With a support Caster Altria from a friend, there should be enough starting gauge to allow for at least two.