It's been a few hours so I suppose I'll tackle this, I also removed prior knowledge as it is probably not needed
Dagger's light attacks can, in theory, one shot Kai, but Kai has multiple ways of avoiding this,
he has intangibility, which he can maintain for a decent amount of time, as well as the chip
Emergency Accumulator, which makes Kai's energy reserves take damage instead of him, which likely would stop some of Dagger's attacks. Outside of Kai's intangibility, he is also very mobile, he can have 2 air jumps (With
Air Jumper and
Function Overload, he can stack those), a
mid-air dash, can create
platforms to keep his momentum, as well as use his hook to... well, hook on either the ground or on Dagger's forcefields to get closer to her
The AP advantage for him is considerable when compared to her forcefields, at about a ~6.34x advantage, those shields are likely going down with 1 or 2 attacks, which is only going to be made faster with Frame Amplifier, which increases the
speed of his attacks, and Clone Array,
which creates a clone that mimicks Kai's movements with a small delay. Another thing worth noting about Kai's melee attacks is that they are
followed by electricity, so it is not out of the world that Kai kills Dagger the moment her forcefield breaks without even needing to get closer.
Dagger is not an immobile target, but I do believe Kai is much more mobile then her, they are likely even or Kai is better in terms of Acrobatics, but he has much more movement options and advantages. A lot of Dagger's hax is not usefull against Kai due to him bieng a robot (A fact that likely does not matter as she can just one shot him), and, once again, Dagger needs only a single hit to kill Kai,
but the scan depicts as it not being instantaneous, so, at the very worst, this would be Inconclusive, as Kai would still have more then enough time to break her shields and kill her.
Overall, both can one shot each other, but Kai would likely win more often then Dagger due to his movement advantage and ways to mitigate Dagger's one shot hits, while Dagger only has her forcefields to stop Kai from killing her in a single attack, so I'm voting Kai