Ness mainers, Yuna already said this, but I'll reiterate why he keeps saying the move is slow.
Take anyone with a move that comes out in like, frame 4... or hell, frame 10. These moves will never be considered slow (as far as getting the actual hitboxes out) because the human brain virutally never can react in such a way that:
- in frame 1, you see the starting animation
- from frame 1 - whatever the frame the move comes out, your brain signals you to hit a specific button, and your finger has to make that movement before said move comes out.
The human brain, top, cannot react in 10 frames like that. Ever fought a level 9 CPU and how they have godly (mechanical) reaction times to your attacks? The human brain simply cannot react in this manner. The only time you will be able to defend yourself successfully from an attack that comes out very fast is if you can predict it ahead of time. If I jump in front of someone and I expect their move that attacks on frame 5, I can set my dodging up ahead of time to avoid it. That is predicting, and virtually all moves that come out under a specific frame amount can only be evaded in this manner (assuming you would be hit otherwise).
Ness's PKT2, without any sort of tricks or glitches of any kind, at the fastest possible curve, comes out on frame 18. The human brain can detect and react to this move because the human brain is fast enough to get a message to you that says, "Hey, something is going to happen, and you need to do something about it." Even if you're tricked into falling for the move somehow, you can always see PKT come out and you can *conjure* PKT happening before it actually happens. Can you still be hit by it? Of course you can. However, the move can be reacted to because no matter what, the fastest possible PKT2 is still slow enough for the human brain to react to.
The move isn't a fully charged Eruption and it isn't something you'd only hit a skilled player with if they had their shield broken or whatever the case is, but no matter what, PKT2 can be reacted to before it actually happens. This is what makes the move *slow.* It's not bad, it's not the best/worst kill move for Ness, it's not anything like that, as far as I'm concerned (as I'm not talking about any of those aspects). The move can always be reacted to so long as the opponent's character CAN react and stay safe.