JBuild and Guide

J is a six-star Beast unit centered around his Ripostes, who can do a little bit of everything, from buffing, shielding, to dealing damage.

Gameplay:

J is a bit of an odd unit in the sense that, while his main gameplay revolves around his Ripostes, he has so many tools in his kit that lets him function in a wide variety of scenarios:

He can provide mini-shields to the team to help with survivability via his Counter card [Heat Treating], his Ripostes deal respectable damage once he ramps up, his Debuff card [Hardness Testing] lets him provide a teamwide DMG Bonus increase, and his self-damage and self-Burn shenanigans can let him kind of slot into both Bloodtithe and Lingering Glow set-ups. 

All of this revolves around his most important skill, [Heat Treating]. He puts up a shield whose durability scales with his self-Burn stacks, and whenever an ally holding the shield is attacked, he will perform a Riposte, [Tempering] that has the following effects:

• Applies 2 Burn stacks on all enemies hit (which then applies 2 stacks of Burn on himself via his Insight);

• Deals self-damage to J based on his Burn stacks via his Insight;

• Increases in damage inversely proportional to J’s remaining HP;

This creates a loop that further lowers J’s HP, increases his Burn stacks, which in turn makes his shield stronger and his Ripostes hit heavier.

His Ultimate, [Over the Haight Street!], is an AoE nuke that inflicts Burn onto the enemy equal to J’s self-Burn stacks, which then deals more damage based on Burn overflow on the enemy. 

Euphoria:

His Euphoria turns J from a somewhat odd jack-of-all-trades, master of none, into a one-man-army that can do almost everything all at once with terrifying potency.

First, his shield goes from a flimsy shield only meant as a vehicle for his Ripostes into an actual, sturdy shield that is capable of protecting the entire team even from the most powerful nukes. He can also passively reinforce and extend his shield’s strength and duration respectively, via [Tempering].

Second, his Ripostes gains a massive increase in multipliers, which allows him to become a powerful Riposte DPS in the right situations. As an aside, his Debuff skill [Hardness Testing] now also counts as a Riposte, and consequently, an Extra Action. His Ultimate also gains massive increase in multipliers, unlocking the option for him to function as a Ritual DPS as well.

Third, he no longer receives damage from his self-Burns. Instead of his damage scaling from his missing HP, all the scaling components in his kit now revolves around his self-Burn stacks:

• He provides a scaling teamwide damage bonus via his Ultimate (previously via his Debuff card);

• He provides a scaling teamwide damage reduction buff via his Insight;

• He provides a scaling teamwide Riposte damage increase via his Insight;

• He cleanses debuffs and control effects on the team once he reaches enough self-burn stacks (except his own self-Burn);

• His [Tempering] gains increased multipliers based on his self-burn stacks;

He also gains passive Moxie gain, allowing him to quickly cycle through his Ultimate.

All of these combined makes J a very potent Sustain whilst having the capability to be a competitive DPS in his own right, opening up new team compositions due to his unique ability to consolidate both the Sustain and DPS roles.

Synergies:

Following his Euphoria upgrade, J’s identity shifts from being a DPS unit into a sustain unit. The versatile nature of his kit allows him to fit in almost any team composition, but there are a few standout units that have particular synergies with him.

• Flutterpage - Aside from heavily buffing J’s [Tempering] strikes, J can perform multiple extra actions in one turn (potentially the the unit with the highest extra action frequency), ensuring Flutterpage’s [Gust] stacks is always above 25.

• Cornerstone - J’s multiple [Tempering] attacks act as wonderful vehicles for Cornerstone's [Trial and Error] damage riders. J’s Riposte related buffs also increase the potency of Cornerstone’s own attacks.

• Ezio Auditore - J is de-facto the best sustain for Ezio, since a big chunk of Ezio’s damage comes from his Ripostes.

• Lopera - J can easily maintain high Burn stacks on the enemy to meet Lopera’s [Right on Target]’s threshold. In return, Lopera provides a good amount of crit for J, a stat he is sorely lacking in.

• Anjo Nala - J is a prime candidate for Anjo Nala’s [Bone and Blood] bond thanks to his extra action frequency. He can potentially fully stack her [Legato Harmony] in one round, and they can perform their Ultimates every single turn.

• Recoleta - There’s a potent synergy when J is played with P1 Recoleta. Her [Flood of Fiction] allows him to perform his Ultimate thrice per round, leading to high damage ceilings.

• Windsong - Not a direct synergy, but J’s frequent extra actions allows Windsong teams to comfortably slot in Lopera, 6, or Rhiannon without needing to worry about managing Flutterpage’s [Gust] stacks.

It’s also good time to mention that since J scales with his self-Burn stacks, which is a Negative Status, you do not want to pair him with units who have Cleansing effects, e.g., Vila, Fatutu, Marsha, Narcissus, etc. Thankfully, most of these units are also Sustain units, so there’s very little chance that you’ll be putting them in the same team anyway.