The Vow of Rivals makes regions stronger and drops a rival ally into Guardian fights, including Chronos himself.
The Vow of Rivals is the most theatrical difficulty option in Hades 2, since it does not just buff enemies, it sends a named rival to fight alongside each Guardian.
It is one of the 16 Vows in the Oath of the Unseen 
, the post-game difficulty system, and it is one of the few that has to be unlocked through a quest rather than simply switched on.
Turn it on and regions grow stronger in various ways, and at its higher rank a rival character joins the boss, turning solo Guardian duels into two-on-one brawls.
This guide covers exactly what the Vow of Rivals does, which rival joins each Guardian, how to unlock both ranks, and how it fits into the wider Oath of the Unseen.
regions grow stronger and a rival joins each Guardian fight.The Vow of Rivals makes regions stronger in various ways and, at its higher rank, summons a named rival to fight alongside the region Guardian.
The wiki describes its effect with the line that adversaries shall rise so that Fear may spread. Mechanically it has two ranks worth 12 Fear, and the headline payoff is the rivals: instead of dueling a Guardian one-on-one, you face the Guardian plus a familiar character who is normally an ally or a side foe. It is the most flavorful Vow in the Oath .
Like every Vow, it contributes Fear, the difficulty measure that earns Nightmare for upgrades at the Silver Pool. Melinoe 
can rescind it freely between runs, and Circe Black Night Banishment can suspend it for a single night while keeping its Fear value, which matters for hitting Fear thresholds.
In short, it is a difficulty knob with personality. The extra Fear is the practical reward; the rival fights are the reason it is the Vow players talk about most.
With the Vow of Rivals active, several Guardians gain a specific rival or a transformed form, and the additions are unique to each fight.
| Guardian | Rival or change | What happens |
|---|---|---|
 Polyphemus | Medea | Medea joins and feeds Polyphemus poison buffs, so any poison ticks until you reach a Curing Pool. |
 Prometheus | Heracles | Heracles assists Prometheus as part of an oath, and you must defeat both to win the fight. |
 Typhon | Chronos | Chronos joins the Summit fight, cannot be damaged, replaces the Zeus stun with Time Bubbles, and adds extra phases. |
 Eris | Aspect of Lucifer | Eris herself transforms into Eris the Lightbringer, swapping to laser attacks and hellfire bombs. |
 Cerberus | Magma arena | The arena gains lava traps and Cerberus gains magma armor, a guard counter, and a barrier. |
The Typhon addition is the nastiest, since Chronos arrives invulnerable and actively interferes. The Medea and Heracles additions turn their Guardian fights into genuine two-target encounters, so bring add-clear and survivability when you enable this Vow.
The Vow of Rivals is not available by default; you unlock its first rank through a short quest and its second rank by beating several Guardians with it active.
The wiki states the first rank: beat Hecate 
twice and Polyphemus once, then speak to Hecate with a plus-one affinity in Erebus, then activate it at the Oath of the Unseen. In practice you stumble into most of this just by playing. After that, the Vow appears in your list to toggle on.
The second rank asks more. You defeat Hecate and Polyphemus with the Vow of Rivals active, defeat Charybdis once, and defeat Scylla and Eris three times each. Clearing those requirements unlocks the higher rank, where the full rival roster shows up across the Guardians.
Unlock the first rank early, then chip at the second. Because rank two needs multiple Guardian wins with the Vow already on, you progress it naturally just by playing with Rivals enabled. Leave it active on runs you are comfortable with and the requirements clear themselves.
The Vow of Rivals is one of 16 Vows in the Oath of the Unseen, the post-game difficulty system that replaces the old Pact of Punishment.
According to the wiki, Nyx created the Oath, and it only appears after Chronos has been defeated at least once, as of patch v1.0. It sits in the Training Grounds between the two route gateways, letting you stack Vows to raise your total Fear before a run, then pursue a marked Guardian with a specified weapon for Nightmare rewards.
Each Vow is worth a set amount of Fear, and the Vow of Rivals at 12 is a hefty single source. Stacking it with other Vows is how you push toward the higher Fear thresholds that gate the best endgame rewards and upgrades.
The Vow of Rivals is one of 16 Vows in the Oath of the Unseen, the post-game difficulty system. It makes regions stronger and, at its higher rank, summons a named rival to fight alongside each Guardian. It has two ranks worth 12 Fear.
It adds a rival to several Guardian fights. Medea joins Polyphemus with poison, Heracles joins Prometheus, and Chronos joins Typhon. Eris transforms into her Lightbringer aspect, and Cerberus gains a magma arena with new defenses.
For the first rank, beat Hecate twice and Polyphemus once, then talk to Hecate with a plus-one affinity in Erebus and activate it at the Oath of the Unseen. The second rank requires defeating several Guardians with the Vow already active.
Yes, if you want Fear. It is worth 12 Fear, a hefty single source toward the thresholds that gate the best endgame rewards. The rival fights are also the most memorable challenge content in the game, but only enable it when your build can handle two targets.
Yes. With the Vow active, Chronos joins the Typhon fight at the Summit. He cannot be damaged and instead interferes, replacing the Zeus stun with Time Bubbles and adding extra phases, so focus Typhon and dodge Chronos.
The Vow of Rivals is worth 12 Fear across its two ranks. Fear is the difficulty measure in the Oath of the Unseen, and beating Guardians at higher Fear earns Nightmare for upgrades at the Silver Pool.
Yes. Circe's Black Night Banishment suspends a Vow for a single night while keeping its Fear value. That lets you hit a Fear threshold without actually fighting the rival, which is useful when chasing reward milestones.
The wiki credits Nyx with creating the Oath of the Unseen and its Vows, with Schelemeus claiming partial credit. It only appears after you defeat Chronos once, and it sits in the Training Grounds between the two route gateways.
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Game data and character art adapted from hades.fandom.com, used under CC BY-SA 3.0. Original content remains the property of the wiki contributors and Supergiant Games.