Mona is a 5-Star Hydro Catalyst character from Mondstadt. She is one of the five standard 5-Star characters that you can obtain by chance in the standard banner or when you lose the character banner’s 50/50 pity mechanic. A versatile support character, Mona can apply Hydro off field as well as provide some crowd control and empower her teammates.
Mona’s Elemental Skill is “Mirror Reflection of Doom”. By pressing the Skill button, she will create a Phantom that’ll taunt enemies and deal Hydro DMG 4 times before exploding. You can alternatively hold the Skill button which will cause Mona to warp back before casting the Phantom at her original location. While the option of putting distance between Mona and the enemy is welcomed, you’ll generally do the press variant instead so that your carry is positioned next to the enemy upon switching. This Skill does the trick, both as a means to apply Hydro off field and as a form of crowd control. There are three caveats however. The first is that the DoT has a low multiplier (44.8% at Lv. 6) and any meaningful DMG is saved for the final explosion. Two, the Phantom only lasts for 5 seconds and you have to wait for 7 seconds for the cooldown to finish. This is technically mitigated by Mona’s A1 passive, which creates a shorter and weaker version of the Phantom when she sprints for 2 seconds. However, you shouldn’t sprint in combat unless you have to and this Phantom will disappear when Mona casts a proper one with her Skill. Third and finally, while the Phantom can provide 3 Hydro particles, it only generates them if the final explosion hits at least one opponent. Should enemies somehow get out of range or they die before the final explosion, you won’t get Energy.
The real reason to use Mona is her Elemental Burst, “Stellaris Phantasm”. With a fair cost of 60 Energy, Mona can summon a wave of water in AoE. Enemies caught in this ability’s range will then be affected by an “Illusory Bubble”, which applies Hydro as well as render them immobile if they’re light enough. Attacking enemies with this effect will apply an “Omen” onto them, which will cause them to take increased DMG by Mona and her teammates. Most attacks will cause the Illusory Bubble to explode, dealing Hydro DMG to the affected enemy. Thanks to a very high multiplier (619% at Lv. 6) and provided that Mona can CRIT and/or proc an Elemental Reaction, the damage caused by bursting the enemy’s bubble can be devastatingly massive.
Even if Mona’s Skill fails to generate Energy, it actually shouldn’t be too difficult to get Mona’s Burst up and ready. This is because, at A4, Mona gains a Hydro DMG Bonus equivalent to 20% of her Energy Recharge. Normally, you should not stack any more Energy Recharge than you need to, if the character in question has enough to reliably get the Burst back up before it finishes its cooldown. 60 is generally the middle level in terms of Energy cost for Elemental Bursts and generally necessitate a little bit of Energy Recharge. While Mona’s Energy Recharge can be stacked the traditional way, you can alternatively stack to the nth degree. You’ll get a sufficient Hydro DMG Bonus stat anyway and you won’t really lose too much in terms of DPS. More importantly, having so much Energy Recharge will generally ensure that Mona gets her Burst back up, even if she doesn’t collect any Hydro particles. Because of this, Mona becomes a very reliable way to deal high Hydro DMG, buff the team with DMG Bonus, and keep enemies at bay. Aside from Artifact sub-stats, building ER on Mona can be achieved with an ER Sands and a weapon with ER as a sub-stat (I recommend the Favonius Codex). The Emblem of Severed Fate set is potentially one of Mona’s best Artifact sets due to its 2-Piece bonus providing an additional 20% ER as well as increasing Mona’s Burst DMG by 25% of the same stat, complimenting her ER scaling.
While Mona is a very strong unit, she does ultimately play second fiddle to Xingqiu. The latter’s Elemental Burst is simply way too good, not only in terms of DMG but also in terms of uptime and frequency. Mona is great for dealing lots of DMG all at once but Xingqiu can set up or trigger Reactions on a frequent basis, which Genshin‘s combat favors. Being a 4-Star character means that Xingqiu and his Constellations are generally easier to get than getting at least one Mona, let alone duplicates of her. Plenty of carries, particularly those of the Pyro element, will welcome Mona but they’ll typically work better with Xingqiu. The one exception that comes to mind is Ganyu as her Charged Attacks don’t really work in tandem with Xingqiu’s Burst. In fact, Ganyu and Mona is currently one of the most hilariously broken combinations in Genshin. Their Talents combined can trigger Frozen on a frequent basis, making enemies easy targets for Ganyu. Mona’s Burst can also augment Ganyu’s Charged Attacks, which are already disgustingly strong. Though an amazing combination, you will of course need to get Ganyu which can be easier said to than done since she is a limited 5-star character.
Out of combat, it is worth noting that Mona has an Alternate Sprint. In fact, she is the very first character in Genshin to officially have this ability. Not only is this faster than a traditional sprint, it also allows Mona to briefly travel across bodies of water without swimming. While this Talent could maybe use some more finetuning, moving Mona in this fashion has become considerably less clunky and more snappy thanks to adjustments made in Version 2.0. It’s pretty helpful for exploration though I will admit that Mona’s Alternate Sprint isn’t as good as Ayaka’s, if only because Ayaka has the extra ability of freezing the water below her when she exits out of her sprint.
I can’t recommend pulling for Mona but that’s only because she’s a standard 5-Star character. Unless you’re willing to spend an indefinite amount of money, leave it to chance. You either get her or you don’t. Building Mona however is something that I strongly recommend. While Xingqiu is the best Hydro support unit, Mona comes pretty close for second place, thanks to her DMG output and versatility. With Hydro characters currently on a premium (seriously, this game needs more), you might as well consider building both you happen to have both.
Thanks for reading!