Ivan the Terrible

Of Ivan’s three skills, his first two are important to his damage dealing capability and should ideally be maxed, with the second taking precedence over the first. His third, on the other hand, can generally be left alone unless the additional cooldown reduction is desired.

• Mental Schism A is primarily used for its NP Gain buff, which fortunately scales with additional levels. While the skill’s offensive benefit does not come close to Ivan’s second skill, the cooldown reduction gained at skill level 6 and 10 grants the buff more uptime and allows Ivan to cleanse his debuffs more often. This skill should be leveled second.
• Innocent Monster (Foreign) A is a very formidable skill, boosting Ivan’s Buster cards’ performance as well as providing some critical stars every turn, with both effects lasting for three turns. Leveling this skill first is generally the most beneficial, as both its constituent effects scale with additional levels, and as a damage battery, the cooldown reduction is also very much appreciated.
• Of Emergency Prerogative A’s three effects, only its attack debuff scales with additional levels. While the cooldown reduction on both Invincibility and buff removal is somewhat beneficial, it only becomes crucial in very specific situations. As such, it is generally fine to leave this skill at a lower level, though maxing it is recommended for those who plan to use Ivan extensively.

“Time for worshipping is finished. Therefore... Next, it's the time to battle.”

A fusion between the human known as Ivan the Terrible and an unknown Demonic Beast, the Lightning Emperor Ivan rules over the Eternally Frozen Empire - Anastasia with equal measures of cruelty and piety. A Rider-class damage dealer Servant with Buster-type AoE NP with a straightforward but effective kit.

As a damage dealer, much of Ivan’s capability to deal damage rests on the various buffs granted by his NP Zveri Krestnyi Khod and second skill Innocent Monster (Foreign). The two Buster Performance boosts they provide are particularly notable, as both last for 3 turns, giving Ivan a considerable lead in terms of sustained damage over his competitors. Furthermore, his skills also enhance his NP Gain (Mental Schism) and provide some amount of critical stars (Innocent Monster (Foreign)), helping him unleash more NPs as well as critical hits, the latter of which is also aided by his naturally high Star Weight. Outside of the damage department, Ivan rounds up his kit with an Invincibility buff, as well as two utility tools in the form of self-debuff removal and buff removal (for all enemies).

The main weakness Ivan’s Buster-centric kit, however, is that it lacks any sort buff capable of boosting his other cards, which lowers his damage outside of burst turns. Furthermore, he also lacks a tool integral to AoE Servants, which is an NP Charge skill. This results in an almost complete dependency on supports to perform instant NPs, which makes him a less desirable option for farming. His last and least significant weakness is the fact that a lot of his skills’ effects often have different usage timings, which, sometimes, makes using them (Emergency Prerogative in particular) a bit of a dilemma.

All said, however, Ivan the Terrible is a highly solid AoE Rider option by all metrics, whose Buster cards are sure to deliver heavy blows to his opponents. While his lack of NP Charge lessens his potential as a farming unit, the damage and utility the Emperor of Lightning provides are more than enough to make up for it.

Three-Turn Buster Performance Boosts

The long durations of Ivan’s offensive buffs ensure that he would be able to get the most out of it, even when his Buster cards are unavailable during the NP Brave chain turn. Furthermore, the Buster Performance boost provided by his NP comes in the form of a debuff on all enemies, which benefits the Emperor’s allies as well as himself.

Good NP Gain and Critical Compatibility 

Aside from having access to a considerable NP Gain buff, Ivan’s naturally high Star Weight enables him to benefit doubly through his reliable critical hits, which also provide an increase to his overall damage. To further improve on his critical capability, Ivan’s second skill provides a decent amount of critical stars every turn, stars which, while not enough to ensure criticals on their own, allow for more flexibility for supports as well as their CE choices.

Good Utility

Ivan’s AoE buff removal on enemies is generally considered to be both rare as well as highly valuable, and this gives him a significant edge over his competitors in terms of flexibility for difficult quests.

Lacks non Card-Specific Damage Boost 

Ivan’s various three-turns Buster performance boosts, on first glance, may seem to be a significant increase to his sustained damage output, but in reality, it is balanced out by the fact that he lacks any sort of neutral damage battery (i.e. Attack Up or Critical Damage Up). While this is less of a problem during NP Brave turns (where Buster cards generally excel), the NP charging properties of Arts and Quick cards are generally preferable outside of it, which reduces the significance of his buffs’ three-turn durations. Fortunately, proper use of damage supports is generally more than enough to make this weakness largely unnoticeable.

No NP Charge Skill

Some extent of farming capability is generally expected of AoE Servants, but it is one of the fields Ivan doesn’t particularly excel at. While his above average NP damage allows him to kill higher-tier mobs more reliably, his lack of instant NP Charge places a restriction on his CE choices, and may force him to rely on supports to unleash early-turn NPs.

Conflicting Skill Effects

While the various effects contained within Ivan’s skills are undoubtedly powerful, their usage timing often conflicts with each other, which means that he’s often unable to gain their full benefits. This aspect of his kit also presents a dilemma in more difficult quests, as Masters will often be forced to choose to forego one effect or the other.

In farming scenarios, Ivan’s preference leans heavily on Starting NP Gauge CEs, in order to ensure as early a NP as possible. On a more general setting, his other choices revolve around various damage boosting effects, such as Attack Up, NP Damage Up, Critical Damage Up, and Buster Performance Up.

• Kaleidoscope / The Imaginary Element: These CEs are generally Ivan’s preferred choice for more mundane runs, as they allow him to unleash a relatively early NP compared to their alternatives. Kaleidoscope in particular allows him to unleash a turn one NP with minimal support from NP Charging allies or Mystic Codes.
• Golden Sumo: Boulder Tournament / Holy Night Supper / Aerial Drive / Starry Nights: These CEs are solid choices for Ivan, especially in well-supported teams where his lack of NP Charge is less of a problem. Granting offensive buffs as well as Starting NP, they help cover Ivan’s lack of universal damage buffs, giving each of his attacks a bit more edge. 
• The Black Grail: Although Ivan has an NP Damage buff built-in to his NP, any scaling concerns this may cause is more than outweighed by the Black Grail’s ridiculous modifier, which still puts it head and shoulders above other options in terms of raw burst damage increase.
• Victor of the Moon / Joint Recital / Glory is With Me: The various critical damage-related CEs in this category can be used when sources of critical stars are aplenty, and like the hybrid Starting NP options, help Ivan’s damage in a more well-rounded way.