Honkai: Star RailMydeiBest build, teams and other guides

Mydei is an extremely powerful HP scaling Destruction DPS. He gains large bonuses to his Max HP while in his special Vendetta state but sets his DEF to 0. Vendetta causes Mydei to become uncontrollable besides his Ultimate, automatically using Enhanced Skills against targets. He is immune to Crowd Control during Vendetta and can shake off getting downed without losing Vendetta up to 3 times, restoring a tremendous amount of his Max HP in the process. He is extremely durable and deals vast amounts of damage, but is functionally in a permanent Auto-battle state in combat.

The combination expy of both G*lgamesh and Kalpas is very cool, and people are very normal about him. His kit reads very much like a typical berserker type character, acting independently from the rest of the party for the most part while being nigh unkillable and dishing out tremendous amounts of damage. Curiously, this isn't really what Mydei is like in the actual story, actually being far more composed and diligent, but uh... I guess the Godslayer knows best?

Mydei's a HP scaler, and like the other notable examples of Blade and Tribbie, results in him being a bit different to build around. The tradeoff is that he gets to turn his natural durability into pure offensive power.

His Skill consumes 50% of his current HP to deal up to 90% of his Max HP as damage to a single enemy, and up to 50% to adjacent targets. If the HP is insufficient, Mydei's HP will be set to 1. This Skill has two separate Enhanced versions, and none of them consume Skill Points at all, making Mydei a true SP-neutral DPS. The HP consumption seems excessive, but it all plays into his kit.

Mydei's Talent is a lengthy one, but it's the cornerstone of his power. Mydei has a Charge mechanic wherein he gains 1 point of Charge for every 1% HP he loses, holding up to 200 points of Charge. At 100 points of Charge, Mydei enters the Vendetta state, restoring 25% Max HP and fully Action Advancing himself. Vendetta will increase Mydei's Max HP by 50% of his current Max HP, essentially providing a 1.5x increase to his Max HP in combat, and the tradeoff is that his DEF stat gets fixed to 0.

This results in Mydei rather easily clearing the 5-digit HP threshold, especially as he has the single highest base HP value in the game, giving him a tremendous boost to survivability and damage. Even though his DEF is set to 0 during Vendetta, this is actually beneficial to his game plan as it helps you to still get a good amount of Charge from enemies attacking you.

During Vendetta, Mydei defers to his own better judgement and will automatically use his first tier Enhanced Skill, Kingslayer Be King (KBK). This consumes 35% Mydei current HP and deals up to 110% of Mydei's Max HP to a single enemy, and 66% to adjacent targets.

When Mydei's Charge reaches 150 points during his Vendetta state, Mydei will immediately gain an Extra Turn and will automatically use his second tier Enhanced Skill, Godslayer Be God (GBG). Aside from the absolutely insanely metal naming convention, Godslayer Be God consumes the 150 points of Charge and deals up to 280% of Mydei's Max HP to a single foe, and 168% to adjacent targets. This is an absolutely ridiculous amount of damage, and it costs neither a Skill Point, nor an actual turn to use, resulting in a hilarious amount of damage over time that doesn't even eat away into buff durations like Action Advances do. Unlike KBK this attack actually can be directed and isn’t fully auto but we’ll get to that in a bit.

Lastly, during Vendetta, should Mydei receive a killing blow, he will not fall, instead clearing all remaining Charge and restoring a massive amount of HP, exiting the Vendetta state. This can occur any number of times per battle, so when Mydei calls himself immortal, he's not joking.

Thus the basic gameplay style of Mydei comes together. He consumes HP to enter his enhanced Vendetta state, gaining autonomy from the player and massacring all who oppose him, and even in death pulling an Anos Voldigoad and being like 'did you really think that killing me would be enough to make me die?'.

The HP consumption is quite exorbitant on its own, meaning if the kit ended here, it would be difficult to sustain this for Mydei alone. But his kit doesn't end there. His Ultimate will restore 20% of Mydei's Max HP and grants 20 points of Charge upon use. He will deal up to 160% of his Max HP to one designated enemy, and 100% to adjacent targets. In addition to this, he will Taunt the foes he hit for 2 turns. This Ultimate will also mark the primary target, causing Mydei's next usage of Godslayer Be God attack to prioritise them until the next time he uses his Ultimate, or until he hits them with GBG.

This Ultimate does so very much for Mydei, and it's an important thing to both consider and have frequent access to. The HP restoration will allow Mydei to have decent sustain all on his own, and the damage is most assuredly nothing to scoff at either, but really the most important parts are the guaranteed Taunt and marking for GBG.

Having a guaranteed Taunt on not one but up to three enemies is impeccable, but having it last for 2 entire turns is extraordinary, as it means Mydei can genuinely redirect a huge number of attacks to himself, getting much more influx of Charge from taking hits and getting a lot of Energy coming back for his own Ultimate.

The marking of an enemy also lets the player specifically indicate to Mydei which enemy you want him to decimate with his next Godslayer Be God, allowing you to somewhat circumvent the downside of Mydei’s extra… chaotic combat style.

Kingslayer Be King, like his regular Skill, restores 30 Energy. Godslayer Be God only restores 10 Energy, but given this is a completely free action, this is quite nice to have on top. Combining this with the plentiful amounts of Energy you'll be getting from taking guaranteed enemy attacks results in Mydei's Energy cost of 160 really not being as difficult to generate as you may initially think.

While Mydei does an absurd amount of damage, it’s well worth noting that the inability to direct his wrath outside of his Ultimate is a distinct disadvantage in target-sensitive encounters you may encounter more often in modes like Pure Fiction and Apocalyptic Shadow.

With the base kit covered, it's time to mention Mydei's Bonus Ability Traces. These are always very important to have fully unlocked for pretty much every character, but for Mydei it's not even up for debate, you have to have every single one unlocked because they massively affect his gameplay for the better.

Mydei's A2 is immense. During the Vendetta state, when Mydei receives a killing blow, he will still heal a huge amount, but will not lose any points of Charge and will not exit the Vendetta state. This complete denial can occur up to 3 times per battle. After these 3 uses are exhausted, Mydei's Vendetta revive will function as normal.

If you thought Mydei was unkillable before, you're in for a shocker. While it is theoretically possible to die after these 3 A2 revives are expended, it's still damn near impossible to actually do so in practice. The Effective Hit Points (EHP) of Mydei with this A2 passive skyrockets to absurd values, and if you genuinely haven't killed whatever you're fighting by the time you need to exit Vendetta to revive, buddy, I don't know how to tell you this...

The other massive benefit of this is that Mydei can much more easily and freely stack points of Charge through his own HP consumption as well as the damage he takes from enemies. With the HP restoration from his Ultimate combined with the occasional HP restore from his Vendetta revivification, Mydei becomes extremely self-sufficient, and as a bonus should realistically never ever die.

Mydei's A4 is short but remarkable. While in Vendetta, Mydei is completely immune to Crowd Control debuffs. He chooses to simply not be affected. This includes all the usual rage inducers, like Freeze, Boss Kafka's Domination, Concussion, and whatever new and heinous things they have planned for the future. Incapable of dying and now incapable of getting stopped.

Lastly, Mydei's A6 is a stat conversion Ability. When battle starts, if Mydei's Max HP exceeds 4000, every 100 excess HP will grant 1.2% CRIT Rate, 2.5% extra Charge when hit by enemies, and an additional 0.75% increase to his Incoming Healing. These benefits max out at an excess 4000 HP, or more tangibly, a Max HP value of at least 8000 out of combat (very important).

This results in his A6 providing a total bonus of 48% CRIT Rate, 100% bonus Charge gained from enemies, and 30% bonus to Incoming Healing. Insane permanent bonuses to be having, and it skyrockets both his damage and his survivability. With all of the Bonus Ability Traces, Mydei now truly embodies the relentless avenger archetype, and can very reasonably be played without a sustain.

In terms of building a team around Mydei, you do run into the same issue that most of the HP scaling DPS have which is that typical ATK buffs, understandably, do nothing. As such, you are encouraged to seek out teammates that provide more generalised buffs like DMG% or RES PEN. Good thing we just got a character like that in Tribbie, who happens to be a fantastic pairing for Mydei. He greatly appreciates the RES PEN Tribbie gives, and Tribbie's personal damage is very significant, and very AoE — a great complement to Mydei's exclusively Blast AoE kit.

Tribbie also helps to compound even more damage onto large HP bosses (not that Mydei struggles with this), and Mydei's absurd Max HP value also returns some benefit to Tribbie due to her A4 Trace granting her Bonus Max HP based on a sum of ally Max HP. In addition to this, Tribbie is similarly extremely SP efficient, so combining her with the fully SP neutral Mydei gives the team a surplus of Skill Points to use for whatever you may want.

As is rapidly becoming tradition, no DPS can be talked about without mentioning Sunday. Unsurprisingly, having a character with a strong Ultimate who wants to take multiple turns means Sunday is a natural fit, being able to provide significant Energy restoration alongside a no-cost 100% Action Advance. Sunday's buffs are also not tied to ATK in any way, being generalised DMG% and CRIT based buffs, so it's even better for a HP scaling DPS like Mydei.

Sunday is quite a contested character in general, so it's good to know that another excellent teammate is the Remembrance Trailblazer. They can also provide a 100% Action Advance to Mydei as well as a large final damage multiplier with their True DMG applying buff. Especially thanks to Mydei's Godslayer Be God being an Extra Action, Mydei can make use of the Trailblazer's strong buff for quite a while. Pairing them alongside either Tribbie or Sunday creates a very potent supporting cast for the vast majority of DPS characters, but especially one such as Mydei who does not scale with ATK.

As mentioned previously, it is actually quite reasonable to run Mydei without a sustain of any kind, since he can very easily redirect enemy attacks to his own nigh immortal body and shrug it off like it's nothing. The same can't really be said for his teammates, so in some cases it's just unavoidable that you have to bring a sustain with you, even if you wanted to run without one.

To that end, you only really have a choice of going with an Abundance sustain over a Preservation sustain, as damage to shields does not grant points of Charge to Mydei, so his charging efficiency in Vendetta actually goes down if you apply consistent shielding.

Luckily your options are quite varied overall, especially since Mydei doesn't consume SP, you'll have a lot more floating around for your sustain unit to use, either to directly heal Mydei or to just funnel more Energy to themselves. In particular, Gallagher and Luocha stand out above the rest as consistent sources of healing for the blood sorcerer, and giving them more frequent uses of their Ultimates can be extremely beneficial.

Gallagher's healing lets Mydei heal more for himself, while Luocha's Abyss Flower helps to heal the party as a whole, especially for allies who are not often attacking by themselves. Luocha also has the very useful emergency healing passive available, keeping Mydei topped off more frequently to take and dish out even more punishment.

Lingsha and Huohuo are decent alternatives, especially since they'll get to very easily spam their Skills for Energy and healing, but their healing values aren’t quite as potent as Gallagher or Luocha’s. Lingsha's Break buff and Huohuo's ATK buff are both completely wasted on Mydei as well. Mydei's not really ever in danger of truly dying, so the role of these two is mostly to keep the rest of the party alive in fights where lots of AoE damage is completely unavoidable.

Aside from those options, you can technically utilise any supports that do not exclusively buff ATK values, such as utilising DEF Down from Pela, or Vulnerability Up from Jiaoqiu. You could potentially also utilise someone like Bronya or Sparkle if you lack Sunday, made more easy thanks to the high SP efficiency of Mydei's teams as a whole.

As per usual, the Eidolons are nice, but by no means a necessity. Mydei's E1 increases the DMG multiplier of the primary target of Godslayer Be God by 30%, and GBG becomes a fully AoE attack, dealing full damage to all targets hit. It's certainly an impressive boost especially in Pure Fiction, but realistically isn't that necessary unless you’re set on ensuring Mydei can function at a high level in all three modes.

E2 will let Mydei ignore 15% DEF when attacking in Vendetta, and converts 40% of healing received into extra Charge, up to 40 points per instance. E4 increases his CRIT DMG by 30% in Vendetta and restores 10% Max HP whenever he takes damage from enemies. Lastly, E6 will cause him to immediately enter Vendetta upon combat start and lowers the Charge cost for Godslayer Be God to 100 points.

Despite the unpleasantness of the forced Auto-battle, Mydei is exceptional, dealing immense damage while being impossible to take down. His extreme self-sufficiency means his teambuilding is flexible and he himself can fit into many other team comps without disrupting the flow, and to top it all off, he still has potential to grow even stronger.

He will vanquish all that seeks to bring ruin. Such is his charge.