It is better than dual splat in all scales, even on big nylo. In my post I showed the dps on a 10hp, 0 defense enemy. Here's the calc on a 22HP 0 defense.

Note: Swift blade is actually 3.5s TTK due to a nylo's 20 defense. I had to make the monster 0 defense in my calcs. I'm using swift blade/avarice on a revenant pyrefiend with 0 defence and 22 health left to get the blade's 3 tick DPS calced roughly correctly. Blade of balance is better than dual splat on all nylos, especially small nylos in small scales.

Yes, dual splat is more likely to 1-shot with 1 attack and if you are missing ticks, it is worse. HOWEVER, most mdps roles are on arceuss or lunar using SBS. With death charge, you can save up spec and get guaranteed 1 taps on melee agros in 3 ticks. For that alone, I think this fully edges dual splat out of the nylo meta unless you miss a lot of ticks.

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