S-TIER | BUILD MERCENAIRE GEMLING COC BLINK (@NickTew) | SAISON 5

Build Video

Build Overview

This Gemling Mercenary build pushes the Cast on Crit formula Spark to its absolute maximum, leveraging the Gemling Legionnaire’s doubled quality effects via Advanced Thaumaturgy across the entire range of triggered spells. Unlike most Cast on Crit builds that rely on a focus, the author instead picks a plain sceptre here to maximize Spirit (up to 366) and unlock, for free, Purity of Fire, Trinity, Alchemists Boon as well as a second Cast on Critical setup entirely dedicated to Arc — which deals more damage here than Comet. The character teleports on a loop thanks to Blink and Temporalis, triggering an avalanche of Comet, Living Bomb, Frost Wall and Ice Nova on every cast via two Cast on Critical setups and one Cast on Elemental Ailment setup.

The rotation is deliberately minimalist: holding right-click is enough to chain teleports and triggers, with most of the work happening automatically through the trigger gems. The character plays Low Life with Mind Over Matter and Pain Attunement (via Atziris Communion), which makes Trinity free while keeping a very comfortable mana cost (around 200 mana for Spark). Without Eldritch Battery, mana management stays simple and avoids the cost doubling that this mechanic usually imposes.

This Gemling Mercenary build reaches an extremely high damage ceiling for an investment of around two mirrors, half of which is concentrated on Temporalis and the Rune Master Fork sceptre — both optional for a more budget-friendly version.

Strengths / Weaknesses

Skill Gem Setup by Step

This build offers 6 progression steps from leveling to the final build. Select a step to see the corresponding gem setup.

Turbo Budget Mid Budget Blink Spam $$$ | Imported Blink Spam $$$ GPU friendly Temporalis + Fork Exped Aldur’s Saga Farming

Turbo Budget

13 skills • 54 gemmes

Virtuous BarrierVirtuous Barrier

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

Pureté du feuPurity of Fire

Siphonnage des élémentsSiphon Elements

ÉtincelleSpark

Reliquats de ManaMana Remnants

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

Mur de glaceFrost Wall

Déclenchement lors de CritiquesCast on Critical

Tempête de feuFirestorm

Bombe de givreFrost Bomb

Explosive TransmutationExplosive Transmutation

Mid Budget

14 skills • 60 gemmes

Virtuous BarrierVirtuous Barrier

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

Pureté du feuPurity of Fire

Siphonnage des élémentsSiphon Elements

ÉtincelleSpark

Reliquats de ManaMana Remnants

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

Mur de glaceFrost Wall

Déclenchement lors de CritiquesCast on Critical

Tempête de feuFirestorm

Bombe de givreFrost Bomb

Déclenchement lors de CritiquesCast on Critical

Explosive TransmutationExplosive Transmutation

Blink Spam $$$ | Imported

21 skills • 89 gemmes

Virtuous BarrierVirtuous Barrier

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

Pureté du feuPurity of Fire

TransfertBlink

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

ÉtincelleSpark

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

Déclenchement lors de CritiquesCast on Critical

Déclenchement lors de CritiquesCast on Critical

Explosive TransmutationExplosive Transmutation

Siphonnage des élémentsSiphon Elements

Reliquats de ManaMana Remnants

Armure arctiqueArctic Armour

Bombe de givreFrost Bomb

Tempête de feuFirestorm

AffaiblissementEnfeeble

Mur de flammesFlame Wall

Nova de glaceIce Nova

Orbe des oragesOrb of Storms

Blink Spam $$$ GPU friendly

21 skills • 89 gemmes

Virtuous BarrierVirtuous Barrier

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

Pureté du feuPurity of Fire

TransfertBlink

Siphon de pouvoirPower Siphon

Puissance absoluePinnacle of Power

ÉtincelleSpark

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

Déclenchement lors de CritiquesCast on Critical

Déclenchement lors de CritiquesCast on Critical

Explosive TransmutationExplosive Transmutation

Siphonnage des élémentsSiphon Elements

Reliquats de ManaMana Remnants

Armure arctiqueArctic Armour

Bombe de givreFrost Bomb

Tempête de feuFirestorm

AffaiblissementEnfeeble

Mur de flammesFlame Wall

Nova de glaceIce Nova

Orbe des oragesOrb of Storms

Temporalis + Fork

17 skills • 56 gemmes

Virtuous BarrierVirtuous Barrier

The Stars AnswerThe Stars Answer

Pureté du feuPurity of Fire

Déclenchement lors de CritiquesCast on Critical

Projection de sortilègesSpellslinger

TransfertBlink

AffaiblissementEnfeeble

Mur de flammesFlame Wall

Faveur de l'alchimisteAlchemist's Boon

ÉtincelleSpark

Déclenchement lors de CritiquesCast on Critical

Siphonnage des élémentsSiphon Elements

Reliquats de ManaMana Remnants

ArchimageArchmage

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

TrinitéTrinity

Orbe des oragesOrb of Storms

Exped Aldur’s Saga Farming

17 skills • 57 gemmes

Virtuous BarrierVirtuous Barrier

The Stars AnswerThe Stars Answer

Pureté de la foudrePurity of Lightning

Déclenchement lors de CritiquesCast on Critical

Projection de sortilègesSpellslinger

AffaiblissementEnfeeble

Mur de flammesFlame Wall

Faveur de l'alchimisteAlchemist's Boon

ÉtincelleSpark

Déclenchement lors de CritiquesCast on Critical

TrinitéTrinity

Siphonnage des élémentsSiphon Elements

Reliquats de ManaMana Remnants

ArchimageArchmage

Orbe des oragesOrb of Storms

Déclenchement lors d'Altérations élémentairesCast on Elemental Ailment

TransfertBlink

Recommended Equipment

• Sceptre: Rune Master Fork with the « gain 5% of Physical Damage as Extra Fire » line to trigger ignite on Arc, or Adonia’s Ego as a high-end alternative.
• Secondary weapon (weapon swap): Wand with Spellslinger, used only to pre-charge the cold infusion before entering a difficult map.
• Gloves: Runic Ward, projectile damage and mana, rarity, chance to gain Arcane Surge.
• Helmet: Energy Shield via Jaquani’s Thesis to unlock Paragon, plus rarity and resistances.
• Amulet: Cast on Crit, Spirit, mana, spell levels and quality of all skills, with Dominion as second passive.
• Ring: Pneumonic Ring (implicit increased mana) with mana cost efficiency, flat mana, cast speed and rarity.
• Boots: cooldown recovery reduction (for Blink), Spirit, mana and rarity.
• Temporalis: equip via weapon swap for continuous teleportation, ideally around a 2-second cooldown.
• Key unique: Headhunter, for critical strike, critical immunity, cast speed and resistance cap.
• Charms/Flasks: Nerve o’ Hope and Stone Charm against freeze and stun, Spirit of the Stag for 30% all resistances, Lavianas for permanent cast speed via Alchemists Boon.

Gameplay Tips

• Pre-load the cold infusion: at the start of a difficult map, swap to the Spellslinger weapon, cast a few spells to generate power, then swap back to your main weapon: your first Spark will already be infused with cold (x3 damage).
• Never stay completely still: some chaos explosions can punish prolonged inaction, even without a visible monster on screen.
• Adapt the setup for Expedition: replace a support gem with Commiserate in the Cast on Critical setup to become immune to the ailments you inflict on yourself (freeze, shock, ignite).
• Archmage disabled: if a visual bug disables Archmage, a simple click is enough to reactivate it — no need to rebuy the gem.
• Farming in a group: this build stays stable even without external buffs, making it an excellent candidate for 6-player Breach.

Why a Sceptre Instead of a Focus on this Gemling Mercenary Build

Most Cast on Crit builds rely on a focus, which provides 70 to 80% extra total damage via spell levels, cast speed, and critical strike. This Gemling Mercenary build prefers a normal sceptre instead, which provides a massive amount of Spirit instead. This extra Spirit unlocks for free Purity of Fire, Trinity, Alchemists Boon and above all a second Cast on Critical setup entirely dedicated to Arc. Result: Trinity alone provides about 66.6% extra damage once at 200 cold/ice affinity, a figure very close to what a focus would offer, while adding a second free spell trigger.

Double Cast on Crit Setup: Arc and Comet

The core of the build relies on two distinct Cast on Critical setups. The first, mounted on the amulet, triggers Arc with Zenith I (for more chains), Dominus Grasp and Arbiters Ignition — Arc chains enough times to almost instantly ignite the target, keeping Elemental Archon at 100% uptime. The second triggers Comet and Living Bomb, usually at a lower level to maximize trigger frequency. On top of that, a third setup, Cast on Elemental Ailment, summons Frost Wall and Ice Nova every time an elemental ailment is inflicted. This triple layering of triggers turns every click into a cascade of explosions.

Weapon Swap Tip: Pre-charging Cold Infusion

Without an active cold infusion, Spark deals noticeably less damage. To avoid the risky first few seconds of a tough map, the author equips a secondary weapon carrying Spellslinger with Power Siphon. By casting a few spells with this weapon before swapping to the main weapon, the character generates energy that immediately infuses the next cold Spark, for a x3 damage multiplier right from the first cast.

Farming Grand Expedition Aldur’s Saga

This Gemling mercenary build tanks 7-rune-slot Expedition maps without issue, including runes usually avoided like the Soul rune. To survive the constant ailments (freeze, shock, ignite) that Expedition inflicts on the player, the author replaces a support gem in his setup Cast on Critical with Commiserate, which applies and immediately removes any ailment received — making the character virtually immune. Ixchel’s Ixchels Torment also replaces another gem on the Cast on Elemental Ailment, in order to offset the mana consumption generated by the massive number of Ice Nova triggered on the toughest monsters.

Skill Tree