Mydei remains one of the most unique Destruction carries in Honkai: Star Rail, distinguished by an HP-heavy scaling system that rewards aggressive self-consumption. Unlike traditional DPS characters who fear low health, Mydei thrives on the edge of death, entering the "Vendetta" state to unleash a barrage of Imaginary damage. As of the current 3.7 meta, his team compositions have evolved significantly with the introduction of specialized supports who can handle his high-frequency action advance and massive HP pool.

Selecting the right teammates for Mydei isn't just about raw damage buffs; it's about managing his Charge accumulation and ensuring he doesn't exit his enhanced state prematurely. Because his Vendetta state renders him uncontrollable, the team must provide passive utility and durable sustain that can survive his innate taunt mechanics.

The Logic Behind Mydei Team Synergies

To build an effective Mydei team, one must account for his Talent, "Blood for Blood." He gains Charge points for every 1% of HP lost. Once he hits 100 points, he advances his action by 100% and enters Vendetta. In this state, his Defense drops to zero, but his Max HP increases significantly. This makes him a literal glass cannon made of pure health.

Teammates who provide Action Advance (like Sunday) or Max HP buffs (like Hyacine) are prioritized. Furthermore, since Mydei consumes HP with every Skill use and takes hits due to his Ultimate’s taunt, high-output healers are non-negotiable. Shielders are generally less effective here, as preventing HP loss actually slows down Mydei’s Charge accumulation, delaying his transition into his strongest state.

The Premium Hypercarry: Sunday and Tribbie Support

This is widely considered the gold standard for Mydei teams in high-end content like Memory of Chaos and Apocalyptic Shadow. This composition focuses on maximizing the uptime of the Vendetta state while layering massive multipliers.

  • Main DPS: Mydei
  • Support 1: Sunday
  • Support 2: Tribbie
  • Sustain: Luocha or HuoHuo

Sunday serves as the primary engine for this team. His ability to provide immediate action advance and energy regeneration allows Mydei to bypass slow natural turns and force HP consumption cycles. Since Mydei’s Skill, "Deaths are Legion, Regrets are None," scales heavily with his Max HP, Sunday’s damage boosts feel impactful.

Tribbie complements this by providing All-Type RES Pen. In the current meta, Tribbie’s barrier mechanic adds extra damage instances when Mydei attacks. Given that Mydei can act multiple times in a row during Vendetta, he triggers Tribbie’s follow-up utility more frequently than almost any other Destruction unit. For sustain, Luocha is the preferred choice for players who want a "set and forget" experience, as his field healing triggers every time Mydei attacks—which is often.

The New Era Meta: Cyrene and Cerydra Combo

With the shift toward tactical burst windows in recent patches, the Cyrene and Cerydra pairing has emerged as a high-skill, high-reward alternative for Mydei. This team is less about constant action advance and more about amplifying the specific damage multipliers of Mydei’s Skill and Ultimate.

  • Main DPS: Mydei
  • Support 1: Cerydra
  • Support 2: Cyrene
  • Sustain: Hyacine

Cerydra is essential here because she allows for precise control over Mydei’s burst timing. Her mechanics convert what used to be random HP-based outbursts into strategically timed damage windows. Cyrene takes this further by converting the actions of other teammates into additional Ultimate triggers for Mydei. This creates a loop where the support units’ turns actually fuel Mydei’s out-of-turn damage.

Hyacine is the specific sustain recommendation for this lineup. As a Chrysos heir, Hyacine increases Mydei’s Max HP ceiling. Since Mydei’s base multipliers are calculated from his HP, a 20-30% increase in Max HP translates directly into a massive DPS gain, far exceeding what a traditional Attack-based buffer could provide.

Dual DPS Setup: The Castorice Synergy

Mydei isn't always restricted to the hypercarry role. He has proven to be an exceptional Sub-DPS or Co-Carry when paired with Castorice. This team thrives on the synergy between Mydei’s HP consumption and Castorice’s Ultimate requirements.

  • Main DPS: Castorice
  • Sub-DPS: Mydei
  • Support: Tribbie or Ruan Mei
  • Sustain: Gallagher

In this configuration, Mydei acts as a battery. His constant HP burning builds up "New Bud" stacks for Castorice, accelerating her Ultimate rotation. While Mydei’s individual damage might be slightly lower than in a hypercarry setup, the total team output is often higher in multi-target scenarios like Pure Fiction. Gallagher is the ideal sustain for this dual-core team due to his "Besotted" debuff, which provides healing based on the attacker’s damage—a perfect match for two high-frequency attackers.

F2P and Budget Options for Mydei

Not every player has access to limited 5-star supports like Sunday or Tribbie. Fortunately, Mydei has a very high floor, meaning he can perform adequately with 4-star units and the Trailblazer.

  • Main DPS: Mydei
  • Support 1: Trailblazer (Remembrance)
  • Support 2: Pela
  • Sustain: Lynx

Lynx is actually a secret MVP for F2P Mydei players. Her Skill not only heals but also increases the target’s Max HP and increases their aggro (if they are Destruction or Preservation). For Mydei, being hit more often is a benefit, as it generates Charge faster through HP loss. Pela provides universal Defense shred, which is highly efficient since Mydei already has high base damage but lacks innate DEF ignore until higher Eidolons. The Remembrance Trailblazer offers Crit DMG buffs and True DMG instances that help Mydei clear mobs without needing premium gear.

Crucial Stat Thresholds for Team Planning

When building a team for Mydei, you must ensure your Mydei hits specific stat breakpoints to make the most of his supports. The most critical factor is his HP.

The 8,000 HP Rule

His Trace, "Bloodied Chiton," provides a significant Crit Rate boost based on every 100 HP exceeding 4,000, up to a cap of 8,000 total HP. If your Mydei is sitting at 6,000 HP, you are leaving a massive amount of free Crit Rate on the table. When choosing a sustain, consider if they provide HP-related buffs. If your relics are sub-optimal, a sustain like Lynx or Hyacine becomes mandatory to bridge the gap to that 8,000 HP threshold.

Speed vs. HP Boots

There is an ongoing debate in the community regarding Speed boots versus HP boots for Mydei. In teams with Sunday or Bronya, HP boots are generally superior because the support handles the action advance, allowing Mydei to focus entirely on his scaling stat. However, in F2P teams or dual-DPS setups where action advance is limited, Speed boots (reaching the 134 or 143 breakpoints) are necessary to ensure he can generate his own Charge points frequently enough.

Positioning and Combat Tactics

Where you place Mydei in the team lineup matters more than you might think. Because his Ultimate applies a Taunt to himself, he will be the target of most single-target and blast attacks from enemies.

  1. With a durable sustain (Luocha/Gallagher): Place Mydei in slot 2 or 3. This allows him to take hits, and the resulting blast damage from enemies will hit the adjacent teammates, generating energy for them as well. Ensure the teammates next to him have decent bulk.
  2. In high-pressure content: Place Mydei in slot 1 or 4. This minimizes the number of teammates who take collateral damage from enemy blast attacks aimed at Mydei.

During combat, the most common mistake is using Mydei’s Ultimate too early. It is often better to wait until he has just exited the Vendetta state to use the Ultimate. This immediately grants him 20 Charge points and restores his HP, shortening the window between his next Vendetta cycle. If you use it while he is already in Vendetta, you might over-cap on Charge and waste the sustain utility of the heal.

Final Recommendations for 3.7 and Beyond

Mydei teams in HSR are currently in a very healthy spot. Whether you are running the high-end Sunday/Tribbie hypercarry or the reliable Lynx/Pela F2P squad, the core principle remains the same: embrace the HP loss.

If you are looking to pull for new units to support your Mydei, prioritize characters that interact with Max HP or Action Advance. While Attack buffers like Tingyun or Asta are functional, they do not scale with Mydei’s kit as efficiently as the newer generation of supports. Focus on reaching that 8,000 HP milestone, pair him with a healer who can keep up with his self-destruction, and watch as he tears through the game's toughest content with his relentless Vendetta cycles.