One final pitch.
If all we had to go on were Sasuke's and Zetsu's statements about Kirin's speed, I'd gladly concede and walk away from the argument. But that's not the case.
We have two omniscient sources—the Third Databook and Second Fanbook—and an additional narrative excerpt from the Second Fanbook, all of which were supervised by Masashi Kishimoto himself. These sources aren't speculation; they’re authoritative, editorially sanctioned perspectives that reinforce the claim of Kirin moving at light speed.
Naturally, these may not be enough to outright override statements from the primary canon—but that hinges on the nature of those statements. In this case, they come from subjective in-universe characters. One of them (Zetsu) has already been shown to be unreliable in this scenario, lacking any prior knowledge of Kirin’s existence or mechanics. The other (Sasuke), while more reliable, arguably understates Kirin’s true potency
Sasuke: Yeah, I don't have any chakra left (not true. Had enough to keep the sharingan active and activate Chidori). I used it up on that fire style jutsu. But... Do you really think I would come here to kill you unprepared?
It only lasts an instant (sure). Just like the Amaterasu, it cannot be blocked or evaded (sasuke evaded amaterasu the chapter directly preceeding this). Now....you wanted it....so here it is. Your death
This jutsu guides the lightning striking down from the heavens (sure, except for one, or 4, big katons creating the justu in the first place). In short, I merely direct it power towards you (regular lightning from the heavens didn’t nuke the uchiha hideout. We see at least 4 lightning bolts hit the ground before kirin with none of the power or narrative importance) .
This jutsu is Kirin. Begone with the thunderclap.
When weighed against this, the omniscient, albeit secondary, sources deserve to be taken seriously—especially when there are multiple, consistent statements reinforcing the same conclusion.
Additionally, there are numerous examples in the primary canon that show lightning-speed attacks are not inherently unmanageable for high-tier shinobi. Zetsu’s statement, when paraphrased, essentially claims: “Lightning-speed attacks are unavoidable.” Not “They’re only unavoidable if you're 5 meters away.” That’s a critical distinction. Therefore, counter-arguments like “Kakashi might be Mach 10 and cut lightning” or “Kankuro was 20km away and dodged it” don't really hold water here.
In summary, we’re not working off a single claim or one vague line. We're dealing with a body of consistent, cross-referenced statements across multiple officially sanctioned sources—all pointing to the same conclusion.
Goodnight.