Beidou is unique among Genshin Impact‘s cast of playable characters in that she’s currently the only one who can parry. While you can just press a button to use her Elemental Skill, “Tidecaller” to deal Electro DMG, its true power materializes when you hold the button. When holding the button, Beidou will form a shield that’ll absorb incoming hits. Release the button and Beidou will swing back at the enemy. How much damage she deals depends on how much Beidou tanks or, provided she has her A1 passive unlocked, if you hold the button right as she is about to get hit. If you do this right, the parry will lots of damage, more so if it crits and/or procs an Elemental Reaction.
Counterattacking with Beidou is most certainly a lot of fun to pull off but to be frank, I find it at odds with Genshin‘s combat loop. Thing is, you can anticipate an enemy’s attack and counter it for massive damage or you could tank if with a shield and go crazy with a bunch of Elemental Skills for the same result. “Tidecaller” with its maximum DMG increase certainly has the number to back it up but timing the skill for that damage is more work for the player to do. Furthermore, a Genshin team comp typically has the player steadily rotating between four characters and their respective abilities. Keeping Beidou on the field and waiting for the enemy AI to cooperate thus sounds a bit counterintuitive. You can switch to Beidou at just the right moment to parry but that does require you to be even better with your timing (and for your internet connection to cooperate).
While countering is the more obvious appeal of her kit, the real reason you’d use Beidou lies more with her Elemental Burst, “Stormbreaker”. Upon activation, Beidou will create a “Thunderbeast’s Targe” around herself which will steadily deal Electro DMG to nearby opponents. This effect does not end if Beidou leaves the field and it will carry over to any character that takes her place. Provided that your carry uses a melee weapon, “Stormbreaker” is an ideal burst to use for triggering an Electro-related reaction multiple times. The downside to this ability is that it has a high Energy cost of 80 and “Tidecaller” generates the most amount of particles if it’s used for counter. This can be compensated by stacking Energy Recharge on Beidou and/or with another Electro character such as Fischl to serve as a battery.
I’ve tried Beidou as a carry and a support and while both are perfectly viable, I slightly favor support as her role in combat. Keeping Beidou on the field does make it easier with timing her Elemental Skill but as mentioned earlier, waiting around to counter is not the most productive thing to do and it’s generally better to switch between characters. I found myself needing to build Beidou’s Physical DMG to compensate the downtime of her abilities which can come at the cost of weakening her Electro DMG. A support build works much better with a team’s rotation and, depending on the artifacts used, it’s better for augmenting Beidou’s Elemental Burst. Most of Beidou’s constellations improve her Burst too.
Speaking of constellations, I don’t think Beidou necessarily needs any of them to do her job. I do however think her C6 is worthwhile as it adds an Electro RES debuff to Beidou’s Elemental Burst, making it great for an Electro-Charged based team. The most immediate boost to Beidou’s viability as a support is her C1. It allows her to create a shield when her Elemental Burst is activated. It’s a nice bonus but I wouldn’t rely too much on it as it absorbs based on Beidou’s Max HP. The only other thing that scales on HP is Beidou’s tanking when using her Elemental Skill so HP should only be built as a bonus through Artifact sub-stats. Luckily, Beidou is a 4-star character so the odds of you eventually getting Beidou to C6 is pretty likely.
Thanks for reading!