Mydei Best Builds, Teams & Relics

Honkai: Star Rail
Last Updated: on Aug 12, 2026 at 22:00 by Holster

Introductions

Mydei is a 5-Star character with the Imaginary element who follows the Path of Destruction. Mydei is an HP-scaling DPS whose kit revolves around building Charge to enter Vendetta, which increases his Max HP, advances his action by 100%, and cycles through his Enhanced Skills to deal increasing damage.
Our Mydei Build Guide will show you the best Light Cones, Relics, and team compositions to help you build the best Mydei.

Mydei's Best Light Cone

Listed below are the Light Cones we recommend for Mydei.

Flame of Blood, Blaze My Path
S1
Increases the wearer's Max HP by 18.0 / 21.0 / 24.0 / 27.0 / 30.0% and Incoming Healing by 20.0 / 25.0 / 30.0 / 35.0 / 40.0%. When using Skill or Ultimate, consumes HP equal to 6.0 / 6.5 / 7.0 / 7.5 / 8.0% of the wearer's Max HP and increases the DMG dealt by this attack by 30.0 / 35.0 / 40.0 / 45.0 / 50.0%. If this effect's consumed HP is greater than 500, the DMG additionally increases by 30.0 / 35.0 / 40.0 / 45.0 / 50.0%. If the current HP is not sufficient, this effect reduces the wearer's current HP down to 1.

Sources: Event Warp (limited)
Flame of Blood, Blaze My Path is Mydei's signature and best-in-slot Light Cone. It gives him a huge DMG boost, high Base HP and additional HP %, while also helping him build his Talent faster.
The Unreachable Side
S1
Increases the wearer's CRIT Rate by 18.0 / 21.0 / 24.0 / 27.0 / 30.0% and increases their Max HP by 18.0 / 21.0 / 24.0 / 27.0 / 30.0%. When the wearer is attacked or consumes their own HP, their DMG increases by 24.0 / 28.0 / 32.0 / 36.0 / 40.0%. This effect is removed after the wearer uses an attack.

Sources: Event Warp (limited)
Another strong option for Mydei however he can already get plenty of CRIT Rate meaning you should ensure not to overcap. Their DMG increase also only triggers either when attacked or after HP is consumed.
A Secret Vow
S5
Increases DMG dealt by the wearer by 20.0 / 25.0 / 30.0 / 35.0 / 40.0%. The wearer also deals an extra 20.0 / 25.0 / 30.0 / 35.0 / 40.0% of DMG to enemies whose current HP percentage is equal to or higher than the wearer's current HP percentage.

Sources: Stellar Warp
Ninja Record: Sound Hunt
S5
Increases the wearer's Max HP by 12.0 / 15.0 / 18.0 / 21.0 / 24.0%. When losing or restoring this unit's HP, increases CRIT DMG by 18.0 / 22.5 / 27.0 / 31.5 / 36.0%, lasting for 2 turn(s). This effect can only trigger once per turn.

Sources: Event Warp (limited)
A decent free-to-play Light Cone for Mydei. He will be able to keep full uptime on the CRIT DMG buff due to his kit revolving around him losing and gaining HP.
Flames Afar
S5
When the wearer's cumulative HP loss during one attack exceeds 25.0% of their Max HP, or if the amount of their own HP consumed at one time is greater than 25.0% of their Max HP, immediately heals the wearer for 15.0% of their Max HP, and at the same time, increases the DMG they deal by 25.0 / 31.3 / 37.5 / 43.8 / 50.0% for 2 turn(s). This effect can only be triggered once every 3 turn(s).

Sources: Forgotten Hall Store
Another free-to-play option but not as good as Ninja Record.

Best Relics and Planar Ornaments for Mydei

Best Relics for Mydei

These are the best Relic sets for Mydei.

As Navigator Isee Sees It
2-Piece Set: Increases ATK by 12.0%.
4-Piece Set: When the wearer enters combat or uses Skill, their Skill and Ultimate DMG dealt increases by 18.0%, stacking up to 3 time(s). At the start of the wearer's turn or after using their Ultimate, removes 1 stack(s) of this effect.
The best relic set for Mydei when his team consists of both Cyrene and Cerydra for optimal performance.
Scholar Lost in Erudition
2-Piece Set: Increases CRIT Rate by 8.0%.
4-Piece Set: Increases DMG dealt by Skill and Ultimate by 20.0%. After using Ultimate, additionally increases the DMG dealt by the next Skill by 25.0%.
Scholar provides Mydei with increased CRIT Rate as well as increased DMG from his Skill and Ultimate, enhancing all of his major damage sources.
Longevous Disciple
2-Piece Set: Increases Max HP by 12.0%.
4-Piece Set: When the wearer is hit or has their HP consumed by an ally or themselves, their CRIT Rate increases by 8.0% for 2 turn(s) and up to 2 stacks.
Another decent Relic set for Mydei if you have no good Scholar pieces. The set increases his Max HP, thereby enhancing his damage output.

Best Planar Ornaments

Bone Collection's Serene Demesne
2-Piece Set: Increases the wearer's Max HP by 12.0%. When the wearer's Max HP is 5000 or higher, increases the wearer's and their memosprite's CRIT DMG by 28.0%.
This is the best Planar set for Mydei, providing additional Max HP and an additional CRIT DMG buff when he reaches 5,000 HP. Reaching this threshold should always be achievable with any of his builds.
Rutilant Arena
2-Piece Set: Increases the wearer's CRIT Rate by 8.0%. When the wearer's current CRIT Rate reaches 70.0% or higher, DMG dealt by Basic ATK and Skill increases by 20.0%.
Another solid option for Mydei. Make sure you don't overcap on CRIT when using this set. It also provides a solid DMG increase to his Basic ATK and Skill.

Mydei's Stat Priority

Body
HP
>
CRIT DMG
Feet
HP
Planar Sphere
HP
>
Imaginary DMG Boost
Link Rope
HP
Stat Priority
CRIT DMG
=
CRIT Rate
>
HP

Recommended Endgame Stats for Mydei

HP
8000+
DEF
1000+
ATK
1400+
SPD
134+
CRIT DMG
160%
CRIT Rate
60%

Traces Priority

Skills Priority
Skill > Ultimate > Talent > Basic
Major Traces Priority
Earth and Water> Bloodied Chiton> Thirty Tyrants

Mydei Build Comments

Character Overview Kit Overview Team Synergy

Character Overview

Mydei is a Main DPS focusing on dealing damage based on his Max HP rather than ATK. His kit revolves around sacrificing his own HP to build Charge, allowing him to enter his powerful Vendetta state and gain huge increases to his Max HP and damage output. Once Mydei enters Vendetta, he becomes much more difficult to control, as he will automatically use his Enhanced Skills while fighting independently. He can also survive multiple killing blows, restore a large amount of HP and continue fighting, making him an extremely durable DPS. However, this comes with the downside of having very little control over his actions outside of his Ultimate.

Overall, Mydei is a very unique DPS who turns losing HP into both offensive power and a way of powering up his Charge. His high HP, self-healing and ability to survive killing attacks make him a very self-sufficient character.

Kit Overview

Mydei's Skill consumes 50% of his current HP to deal damage based on his Max HP. As a blast attack it deals damage to the main target as well as nearby enemies, and the Enhanced versions of his Skill do not consume Skill Points, making Mydei very Skill Point-efficient.

His Talent is the most important part of his kit. Mydei gains Charge whenever he loses HP, with every 1% HP lost providing 1 Charge. Once he reaches 100 Charge, he enters Vendetta, restores some of his HP and immediately Advances his Action. Vendetta also increases his Max HP considerably, although his DEF is reduced to 0 while the state is active. During Vendetta, Mydei will automatically use Kingslayer Be King, an Enhanced Skill that consumes part of his HP to deal a large amount of HP-scaling damage. When he reaches 150 Charge, he gains an Extra Turn and uses Godslayer Be God. This powerful attack consumes his Charge and deals massive damage without using a Skill Point or taking up a normal turn.

Mydei's Ultimate is also important for keeping his kit running. It restores some of his HP, gives him additional Charge and deals HP-scaling damage to the target and nearby enemies. It also Taunts enemies for two turns, encouraging them to attack Mydei and helping him generate even more Charge. The Ultimate also marks an enemy, allowing his next Godslayer Be God to prioritise that target.

One of Mydei's biggest strengths is his ability to survive killing damage. When he would normally be defeated during Vendetta, he instead restores a large amount of HP and can continue fighting. His Bonus Traces make this even stronger, giving him additional chances to survive, immunity to Crowd Control during Vendetta and further bonuses to CRIT Rate, Charge generation and Incoming Healing based on his Max HP. When building Mydei, focus mainly on reaching 8,000 HP, which maximises the effects of his Traces and Talent.

Team Synergy

Mydei is a little different when it comes to team building because most of his damage comes from his Max HP rather than ATK like many standard DPS characters. This means characters that mainly provide ATK buffs aren't going to be as useful, so you generally want supports that can increase his overall damage, help him take more actions or provide useful HP related buffs.

Cyrene is one of the best characters to pair with Mydei and is a great addition to his strongest teams. Her Ultimate can trigger Mydei's Godslayer Be God while also giving it a large CRIT DMG increase, allowing him to use one of his strongest attacks more frequently and with even higher damage. Cyrene is definitely a character worth considering for his team. If you don't have Cyrene, Sunday is still one of Mydei's strongest alternatives. His Action Advance allows Mydei to take more actions, while his Energy and damage buffs help him use his Ultimate and powerful attacks more frequently. A team of Mydei, Sunday, Tribbie, and a healer is therefore still a very solid team if you're missing some of his newer teammates.

Hyacine is another strong choice, especially when she's being used alongside Cyrene. She provides the healing Mydei's team needs while also helping Cyrene build towards her Ultimate more consistently. Her HP related effects are also useful for Mydei, making Mydei, Cyrene, Hyacine and Tribbie a very strong team.

Tribbie is a great option for the remaining support slot. She provides buffs that Mydei can actually make good use of, including increased damage and RES PEN, while also dealing damage herself. This makes her particularly useful in a team where Mydei is already being supported by Cyrene and Hyacine.

Remembrance Trailblazer is another option if you don't have Tribbie or would rather use them in another team. They can provide additional support for Mydei while also working well with Cyrene, making them a good alternative without requiring another limited character.

Cerydra can also be used with Mydei, particularly in teams focused on getting more value from his Skill attacks. She can work very well alongside Cyrene, although I wouldn't say you need to use Cerydra if you already have Tribbie available.

For the sustain slot, Hyacine is the preferred option for the Cyrene teams, but characters such as Luocha and Gallagher can still work well if you don't have her. Mydei can take a huge amount of damage himself, but keeping the rest of the team alive is still important, particularly in longer fights. Overall, I recommend Mydei, Cyrene, Hyacine, and Tribbie as the most straightforward team to build around. If you have Cerydra and want to focus more heavily on Mydei's personal damage, she can also be used in place of Tribbie. If you're missing Cyrene, Sunday and Tribbie are still a strong combination to build around.

Mydei's Best Teams

To learn all about Mydei's synergies and best team compositions, check out our dedicated Mydei team page below:

Mydei's Best Eidolons

  • E1 – E1 increases the damage dealt by Godslayer Be God and is a great stopping point for players who don't want to invest further in Mydei's kit.
  • E6 – E6 is Mydei's second-best Eidolon in terms of priority. When Mydei enters battle, he immediately enters Vendetta, and the Charge needed to activate Godslayer Be God is lowered to just 100, allowing him to activate it more frequently.
  • E2 – E2 is Mydei's third-best Eidolon. While Mydei is in Vendetta, he ignores 15% of the enemy's DEF and converts healing into Charge, improving the uptime of his Enhanced Skill.
  • E4 – E4 is Mydei's lowest-priority Eidolon. It provides a CRIT DMG buff and restores some HP when an enemy attacks him. However, Mydei is likely to have enough CRIT DMG without this buff.
Holster
Holster
Guide Author
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Holster is a passionate gacha gamer who spends her time exploring the worlds of Genshin Impact and Honkai: Star Rail. Whether she's pulling for her favorite characters, building new team comps or exploring what the game has to offer.