Mona Build and Guide

Mona is a 5-star Hydro Catalyst user who is most commonly played as a support, with a specialty in Vaporize teams. She provides immensely potent buffs with her Burst, whose limited duration can be extended via Mona’s Normal Attacks. As a Hexerei unit, she also features important synergies with other characters in the faction.

As mentioned, Mona’s kit revolves around her Burst. When looking at it, its most eye-catching feature is the fantastic DMG% buff it offers against enemies affected by its “Omen” debuff - up to a whopping 60% DMG Bonus at Talent Level 10. The second is its measly 5-second duration, which threatens to render the first aspect useless. 

Thankfully, the listed duration is deceptive on its own merits and thanks to her Hexerei Passive can also be played around. When used, Mona’s Burst applies its Omen debuff alongside encasing the enemy in a “Bubble” - with the Omen debuff timer not ticking down until the Bubble is “popped”. In most cases, this happens after any attack to deal a large instance of Hydro damage; however, what actually pops the bubble is the Poise damage it receives from the attack. The simplest implication of this is that using abilities with no attack or attacks that do not deal Poise damage like Hu Tao’s Skill allow the bubble, and thus the Omen debuff, to exist longer. A less obvious interaction is that Frozen enemies do not sustain poise damage. This means that if an enemy remains Frozen, the Bubble will last its full lifespan of 8 seconds before popping, allowing for an Omen debuff that lasts 13 seconds against Freezable enemies.

Nonetheless, this can be inconsistent and matchup-reliant, and a more reliable solution can be found on her Hexerei Passive. This allows her Normal and Charged Attacks to grant her an “Astral Glow of Mercury” stack; more crucially, it extends the duration of an existing Omen debuff on an enemy by 2 seconds to a maximum of 8, meaning Mona can access a 13-second duration Omen as long as she is spared some field time. The Astral Glow of Mercury stacks themselves simply offer a 5% Reaction DMG Bonus to the next instance of Vaporize damage, stacking up to 3 times - acting as a further incentive for Mona to take field time.

The rest of her base kit is relatively unremarkable. Her Skill spawns a “Phantom” which lasts 5 seconds, taunting enemies and dealing Hydro damage every second before a final “explosion”. Since the particle generation of the Skill is tied to the explosion, Mona can sometimes struggle to catch her own particles which can prove problematic for her ER requirements.

Her Normal and Charged Attacks are fairly standard, but unlike most supports, Mona has good incentive to use them. Her first two Normal Attacks are fairly quick, subsequently featuring a brief teleport for her third attack before ending things with her similarly rapid fourth. Her Charged Attack, meanwhile, notably lacks an internal cooldown - meaning that it can apply Hydro whenever it is used. Mona’s Charged Attack becomes more relevant when using her as a DPS, though she is often a poor choice for one at C0. Her second Ascension Passive is similarly tied to her role as a DPS, increasing Mona’s Hydro DMG Bonus% by 20% of her Energy Recharge%.

Mona has an alternate Sprint that lets her apply Hydro to nearby enemies, with her first Ascension Passive additionally allowing her to create a short-lived Phantom after Dashing for 2 seconds. Their extra effects are rarely helpful, with her Dash typically only being used for its core functionality. 

Finally, as a Standard character, Mona’s Constellations are relatively accessible and remarkably powerful - especially with the buffs from her Hexerei Passive. Her C1 increases the effectiveness of Hydro reactions, though the Freeze duration extension is bugged and does not work; with her Hexerei Passive, this boost is 60% more effective when triggered by off-field characters. In practice, this simply serves as a nice bonus to her Vaporize teams. C2’s base effect is disappointing, offering her Normal Attacks a 20% chance to trigger a Charged Attack without interrupting Mona - at its worst, this can even disrupt reaction setups! Her Hexerei Passive thankfully gives it a significant buff, allowing her to guarantee the effect once when using a Normal Attack within 5 seconds of her Burst and additionally allowing Mona’s Charged Attacks to provide a significant 80 Elemental Mastery to the team. This makes extending her Omen duration easier, while providing another boost to her Vaporize compositions. C4 tends to be around the point where Mona begins to outshine her premium competition in a significant number of teams. It allows Mona’s Omen to provide a rare 15% CRIT Rate buff to allies, with Hexerei characters additionally receiving 15% CRIT DMG. 

Her C6 is yet another Constellation with a mediocre base effect, granting a 60% DMG Bonus to her Charged Attacks for every second she wastes using her Alternate Dash for a maximum 180% DMG Bonus. Its Hexerei buff takes this concept of benefitting her personal damage, then dials it up several notches: it allows her Charged Attacks to gain the aforementioned DMG Bonus passively when a nearby enemy with the Omen debuff exists, while additionally doubling the total damage it deals to them. With these bonuses, Mona can use her own buffs to shine as a competent DPS by Vaporizing her Charged Attacks.