How Weapon Synergy Works
You carry two weapons once you buy the second loadout slot for 25,000 Coins, and you swap between them with T. A synergy is the bonus that pair pays out, and there are exactly two outcomes:
- A named pair pays its own stat, such as +10% damage or +15% max health.
- Any other combination of two equipped weapons pays a flat +5% damage.
There is no menu to unlock either outcome; the bonus applies while both weapons sit in the two slots. Because the fallback is positive, leaving the second slot empty costs the flat bonus on every fight.
All Six Named Pairs
The in-game name is what the loadout screen shows. The character column is the anime alias the same weapon is known by. The two trackers that publish pairs agree on all six rows and on every value except the max health figure on the Dragon Eclipse pair.
| Pair (in-game names) | Characters | Bonus |
|---|---|---|
| Cursed King + Immortal Sovereign | Sukuna + Alucard | +10% damage |
| Rubber Man + Divine Emperor | Luffy + Shanks | +15% max health |
| Cosmic Warrior + Thunder Prodigy | Goku + Killua | −10% cooldowns |
| Twisted Agony + King’s Gambit | Juuzou + Nagumo | +20% ultimate charge |
| Dragon Eclipse + Lights of Divinity | Guts + Saber | +5% damage, +8% health † |
| Cataclysm + Lights of Divinity | Miyabi + Saber | +8% speed, −5% cooldowns |
| Any other pair | — | +5% damage |
† One tracker writes the health half of the Dragon Eclipse pair as +8%, another writes +8 Max HP with no percent sign. The unit is unresolved, so the percentage is shown here as the more widely repeated reading, not as the confirmed one.
Lights of Divinity (Saber) is the only weapon with two official partners, so it is the safest thing to leave in a second slot when nothing else fits: it completes a pair whichever of its two partners you already own. Flame Director (Hu Tao) arrived after the pair list and has no published partner, so it takes the flat +5% damage.
Which Pair Fits Your Account
The bonus is the smaller half of the decision. A pair only pays out when you own both halves, and the halves can sit in different rarity brackets:
- Cursed King + Immortal Sovereign — both Arcane, so both sit at the 350-pull Arsenal milestone.
- Rubber Man + Divine Emperor — an Epic starter plus an Arcane pull, so the pair is reachable without two top-bracket weapons.
- Cosmic Warrior + Thunder Prodigy — both starter weapons. The cooldown bonus is the one pair a new account can switch on immediately.
- Twisted Agony + King’s Gambit — both Legendary from the Arsenal banner, which makes it the cheapest complete pair to aim for.
- Dragon Eclipse or Cataclysm + Lights of Divinity — one Mythic plus a Mythic or a Lyth, so the Saber half is the shared cost.
Read that list against your own inventory before you spend pulls. Which of the two weapons is stronger is a separate question, and the weapons database and tier dashboard cover it.
The Swap Bonus Is a Separate Effect
Swapping weapons manually during a fight grants the weapon you switch to +20% damage for 4 seconds. Both published pages describe that as a separate effect from the pair bonus and say the two stack, so the practical rotation is to spend one weapon’s skills, swap, then fire the other weapon’s burst inside the four-second window.
Conflicts and What No Source Settles
- Does a named pair replace the flat +5%? No source says whether the named bonus is the only bonus or the named bonus plus the flat +5%. Do not assume the two stack; the difference is 5 percentage points of damage on every pair above.
- The Dragon Eclipse health unit. +8% or +8 Max HP are both published, and neither tracker shows the panel behind the number.
- Combining order. How the pair bonus, the swap bonus, traits, accessories and titles add or multiply together is unpublished. Treat the pair bonus as its own line until the in-game stat panel shows the total.
- When synergies arrived. One page dates them to an October 2 performance patch. No second source repeats that date, so it stays a single-source claim.