Alright, let me give an actual argument for Ichigo.
Ichigo’s high speed movement technique while in his Fullbring Bankai state would incorporate aspects of Sonido, Shunpo, and Bringer Light as Ichigo makes use of his Shinigami, Hollow, and Fullbring powers while in this form. This gives Ichigo a bit of an advantage when it comes to high speed movement (HSM) techniques, as not only does combining different HSM techniques provide a greater speed amp than just a regular Shunpo (which is already consistently an FTE amp), but it also makes Ichigo harder to sense as Sonido and Bringer Light both either entirely bypass or make it extremely difficult for extrasensory techniques to sense. So, Ichigo’s HSM technique should be superior to Naruto’s body flicker, as body flicker and Shunpo are both portrayed as FTE amps, and Ichigo’s HSM technique is well beyond that of a Shunpo amp. Not to mention, Naruto would have a harder time tracking Ichigo than he would normally. And to top it off, Ichigo is consistently able to react to FTE movement techniques as early as the Soul Society arc when he does so against Byakuya. Hence, I believe Ichigo handily takes it in the speed department here when you compare what their respective speed amps can do.
The next point is an actual argument for Ichigo’s high temperature. The trillion degree calc is just blatantly not accepted and not useable, shame on whichever Bleach goon brought that up. However, the heat of Ichigo’s Black Getsuga is far I’ll far beyond Naruto’s resistances. Thanks to Klub Outside, we know that Royd Yhwach was only 70-80% of actual Yhwach’s capabilities (aka real Yhwach has better abilities, resistances, and power). Royd Yhwach was able to withstand the 15 million degree C passive heat aura of Yama’s Bankai. Meanwhile, Ichigo’s Black Getsuga was able to burn the actual Yhwach. Meaning that FB Bankai Ichigo’s Black Getsuga would have heat on the order of millions of degrees C, which would vaporize Naruto on impact, as Naruto’s accepted heat resistances on wiki are nowhere closer to that value. All of this means is that if Ichigo tags Naruto with a single Black Getsuga, it’s victory for Ichigo.
Lastly, I’d like to address the corruption points since 1) the Bleach supporters cannot articulate that point to save their lives and 2) the Naruto supporters are misunderstanding how Hollow corruption functions. Hollow corruption does take immediate effect on those without antibodies when it’s delivered in high enough dosages. We see this verbatim with the Hollow pills Kisuke distributes to the Captains, as the second they Hollowfy their Bankai, the Sternritter fountain blood from their bodies and cease functioning (as seen with Cang Du and BG9). However, this is not the case for all Sternritter, exceptionally powerful Schrift holders (like Bambi and Quilge for example) have some level of resistance to this corruption. When Komamura’s Bankai Hollowfies Bambi don’t adversely affected at all, and Quilge is able to incorporate Ayon (one of the stronger Hollows alive in the series at this point) into his very being without adverse affects. I bring this up to dispel the notion that Hollow corruption is this slow steady disease. It is very much quick, almost instant, in high dosages for those that lack sufficient antibodies and/or the proper resistances. So, the reason Quilge doesn’t get Hollow corrupted GG by Ichigo is because he has the capability to resist the corruption (as seen by being able to incorporate Ayon), and as for the Bambis we know they possess the capability to resist as well (we see this with Bambietta, and the rest of the troupe are rather comparable to each other). Furthermore, True Shikai Ichigo has mastery over his powers, his Hollow powers normally lay dormant in True Shikai (as seen with how he had to wake White up), and until he fights Yhwach he’s constantly holding back as to not kill the Sternritter. All of the instances of “but why didn’t Ichigo auto Hollow corruption GG them” are easily explained away by the people he fights having capabilities of resisting said corruption or Ichigo actively trying not to kill them. After all, the very plot significant reason that no one could steal Ichigo’s Bankai was due to his immense Hollow power that intertwined with his Shinigami powers. So, yes Naruto, who lacks any resistance to Hollow corruption, would very shortly after the battle starts begin to weaken and deteriorate as his very soul becomes poisoned by Hollow reiatsu.
Putting all this together, I believe there’s good reason to claim Ichigo takes it here. Superior speed amp techniques, blatant one shot techniques he can spam, as well as a passive Hollow corruption that’ll make Naruto weaker as the fight goes on, leads me to believe Ichigo should take this. Without means to blitz and one shot Ichigo, the fight will inevitably drag out long enough for Ichigo to tag a weakened Naruto with a Black Getsuga, turning him to vapor.
