Kernel Hearts Builds: Best Vessel Loadouts, Memento Synergies & Combat Tips for the Tower of Babel
Master Kernel Hearts builds with our guide to vessels, Mementos, Relics, tech tree upgrades, and co-op combat strategies.
Why Kernel Hearts Builds Matter Right Now
Kernel Hearts sends you into the Folktale Fields with a simple mantra: be bold, accept death, and hit things. But when the full game launches September 17, the players who climb highest in the Tower of Babel will be the ones who plan their Kernel Hearts builds with real intent rather than hoping random drops carry the run. Whether you're playing the demo solo or rounding up a full four-player M.A.H.O.U. Unit, understanding how vessels, Mementos, Relics, and the tech tree fit together is the difference between a run that ends in ashes and one that ends with God on the ground.
These Kernel Hearts builds matter more now than ever because the final balance pass, detailed by Game Director Akira in the latest Steam community update, made Mementos and Relics scale with player level so every choice feels rewarding. Enemy encounters were also tuned to feel less spongy, which means your offensive output matters in a way it didn't in earlier demo builds. If you're about to start a fresh run, the decisions you make before the first swing are just as important as the ones you make mid-combat.
Understanding Kernel Hearts Builds: The Core Systems
Kernel Hearts is a multiplayer co-op roguelike action RPG from developer Ephemera Games. You play as a magical girl in the M.A.H.O.U. Unit, fighting through angelic creatures to dethrone God and save a world drowning in ashes. The demo gives you a taste of the opening area, but the full game spans roughly seven floors of tower-climbing chaos compared to the demo's two.
A successful build in this game lives at the intersection of three systems that stack on top of each other:
- Your vessel choice defines your base combat identity and playstyle.
- Mementos and Relics shape the run-by-run power of your chosen strategy.
- The tech tree provides permanent upgrades that make future runs stronger.
| System | What It Does | Build Impact |
|---|---|---|
| Vessel | Determines your weapon, movement style, and special abilities | Sets the foundation for every build decision |
| Mementos & Relics | In-run pickups that modify combat and stats | Determine how your build plays moment to moment |
| Tech Tree | Permanent upgrades between runs (HP, defense, attack, etc.) | Raises the long-term power ceiling of every build |
The key insight for new players is that nothing in Kernel Hearts exists in a vacuum. A defensive vessel with offensive Relics plays completely differently from the same vessel with sustain-focused Mementos. According to the official Kernel Hearts Steam page, the game is built around gathering allies, eliminating angels, and transforming into a Magical Girl — and that transformation extends to how you assemble your loadout.
Vessel Deep Dive: Fernet the Spiritmancer
According to the Epic Games Store hands-on preview of the demo, the standout vessel is Fernet, a Spiritmancer who is intentionally balanced between offense and defense. She dashes around the battlefield with a one-handed sword, strings together dodges and blocks, and calls on familiars to assist in combat. If you're looking for a forgiving entry point to test your first Kernel Hearts builds, Fernet is it.
Her hybrid nature means you can push her in multiple directions depending on which upgrades you prioritize. The official preview describes her as "offensively and defensively balanced," which tells us she doesn't hard-force a single playstyle. That makes her an ideal lab rat for experimenting with different build philosophies before committing to a niche.
| Combat Tool | Function | Build Direction |
|---|---|---|
| One-Handed Sword | Primary melee damage | Pair with attack-focused tech nodes and Relics |
| Dash & Dodge | Mobility and evasion | Supports an aggressive, hit-and-run style |
| Block | Damage mitigation | Pairs well with tanky or sustain-focused builds |
| Familiars | Summoned assistance in battle | Favors utility and pressure over raw stats |
If you put the work in during the demo, you can unlock at least one additional vessel, so don't assume Fernet is your only option. But until the full roster is revealed, she's the most documented character we can build around, and her flexible kit rewards smart decision-making over muscle memory.
Best Kernel Hearts Build Archetypes
Based on the confirmed mechanics and developer commentary, these four Kernel Hearts builds are worth testing when you load up your next run. Each one leans into a different strength of the game's combat loop, so pick the one that matches your playstyle or your team's needs.
1. The Balanced Spiritmancer
This is the default Fernet experience: a little bit of everything. You'll want to split your tech tree investment between HP and attack, then grab Mementos and Relics that improve consistency rather than burst potential. The goal is to keep every tool in her kit viable — sword swings, blocks, and familiar summons — so you can react to any enemy type without a glaring weakness.
- Best for: Players learning the game or running solo
- Tech focus: Even split between HP and attack
- Gear preference: Relics that boost overall damage or survivability
2. The Unkillable Frontline
This build maximizes defense and HP on the tech tree, then uses Fernet's block and dodge tools to outlast enemies. In co-op, this arche
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