I’d say they’re relatively side grades that comes down to smaller differences. Namely that the Kuva Nukor has an extra 2 meters range on the chain effect, but the Tenet Cycron has innate punch through, and can chain 2 times from each target hit with the main beam, vs the Nukor chaining 2 times from just the initial target normally.

Specifically, the Tenet Cycron has chains 7 meters from target, the Kuva Nukor has chains 9 meters from target, but the Tenet Cycron can potentially chain to more targets at closer range due to punch through.

Other specifics include the Tenet Cycron having 28 meters range vs 29 meters for the Kuva Nukor, which isn’t much difference, as well as Tenet Cycron having a slightly higher base fire rate, which means the lower status chance evens out quickly.

And potentially more or less relevant, the Tenet Cycron has recharging ammo, as opposed to the regular reloading of Kuva Nukor, they roughly add up to the same reload time of 2 seconds for a full reload it seems, but the recharge can be partial in less time in addition to not needing ammo pickups, but the Kuva Nukor can fire longer without reloading.

Oh, and I nearly forgot, the Kuva Nukor causes the hidden microwave status effect, which counts as a status for galvanized status mods and certain other effects, the status itself just makes the hit body part a bit larger and thus easier to hit so long as other parts don’t cover it from also getting affected by it.