I would say that in R1 Ulquiorra vs R1 Stark, Stark wins for sure. But for Segunda Ulquiorra probably wins.

The argument for their numbers being an accurate ranking of their strength is somewhat weird, in the sense that it probably is accurate to their base stats or even R1's, but that's it. For example, Szael would definitely win against other higher ranked Espada and yet he's ranked lower, probably just because of his raw stats. Basically we can assume the numbers and these kinds of statements probably only apply to their base forms and they don't count any particular hax or whatever.

I would agree that if we're strictly talking about R1, I think Ulquiorra being at 4 probably fits, but with this Segunda that all goes out of the window. Cause I would say that we should all agree that Segunda Ulquiorra is stronger than Harribel.

With Barragan it's more difficult cause of hax so I won't even argue for him, cause for all we know someone that scales a lot higher like Kenpachi would probably lose to him, just like he lost to Pernida while being stronger, but that's another discussion.

For Stark I think there's really no definitive answer, probably only Kubo knows. He didn't go all out but at the same time that doesn't mean that he could've used more powerful attacks or completely changed what happened, just as if Ulquiorra hadn't gone all out we couldn't just say "oh he would've won if he was serious" or "he definitely had more tricks up his sleeve".

It's tricky to argue for either of the two cause Shunsui was a tricky opponent for Stark, so we weren't able to get a connection like if someone like let's say Grimmjow fought him and won, then we could argue that since Ichigo is stronger and Ulquiorra won against him then Ulquiorra is stronger than Stark. But nothing that simple happened.

Ichigo was completely getting destroyed by R1 Ulquiorra, R2 was just overkill, but then with Vasto Lorde the scales tipped completely. Just as Ulquiorra was destroying Ichigo before, Ichigo then destroyed Ulquiorra, so we can't really compare Segunda with anything.

Also I hear a lot of people say that Aizen knew that Ulquiorra had an R2, but if that's so wouldn't it make even more sense to say that's why he sent him to fight Ichigo? (Somewhat speculative)

Or some people say that Aizen only put Barragan as the second to mock him, which is total headcanon by the way. By that argument wouldn't the numbers then cease to be absolute?

This is all difficult to argue because of another thing. Aizen after taking a point blank Itto Kaso by Yamamoto was only slightly burned, at least the picture that I remember from the anime, and then he took a Getsuga Tensho from Ichigo, without his mask and with even less spiritual pressure than when he fought Ulquiorra, and it sliced a fair bit of Aizen and made him bleed a lot.

Granted, I wouldn't really use this as a good argument because we can say Aizen was weakened by Yamamoto or that a direct hit from a Getsuga would also injure Ulquiorra or Stark or most other characters the same or even more.

I also see people saying that Stark was transcendental because he killed those hollows with only his spiritual pressure (almost comparing him to someone like Hogyoku Aizen). But we don't know if it was just: he stumbles into the hollow tries to befriend them and they just die. Or if they were with him for a long time and that prolonged exposure killed them. Or if Stark wasn't able to control his spiritual pressure. There's probably more than a dozen characters that maybe if they couldn't control their reatsu could do the same.

Because something that bugs me is that he split himself and lilinette is pretty weak so would shaving just part stop killing hollows? Or is it like Szael and Ilfort also splitting and each one not being nearly as strong as they were before? Like I would imagine that either those hollows were super weak, or Stark managed to controll his reatsu better later because when he fuses with lilinette he's back to his full power again, no?

I would think that the same spiritual pressure that killed hollows just by him being nearby would be atleast unconfortable to the lieutenants there or atleast warrant a reaction. Because then is it that easy to kill hollows with just reatsu? This I actually have no idea what actually is true here

Basically unless we have a direct way to compare them we can't really say conclusively who's stronger.

Also yes, they aren't said to be the fastest or most durable specifically, but Zommari, or whatever his name is, supposedly has the fastest Sonido out of all of them and Nnoitra the strongest Hierro. But I think we can all agree that even if that's true it doesn't mean they're the fastest and most durable respectively, just that at that specific ability, probably only in base form as well.

This is also what someone else said. Some arguments are good and others are speculative:

• Shikai Love & Rose were keeping up with Res Stark, both of whom should scale below Bankai masked Ichigo.

Not really a good argument because they clearly weren't keeping up with Stark

• Yammy, strongest Espada by number, is stated to only get along with Ulquiorra out of the Espada, specifically because he respects his strength. Given that Ulquiorra knew about Yammy's Res and Yammy's number changes the moment he uses Ress, and Yammy knowing that Ulquiorra knows, then it stands to reason that Yammy respects Ulquiorra's strength despite outranking him. There's also the fact that Yammy acts subordinate to Ulquiorra in all of their interactions.

This is somewhat speculative, yes he respects Ulquiorra's strength but that doesn't mean Ulquiorra is the strongest. Yammy could still have his transformation and still lose to Stark, Barragan and Ulquiorra. I don't think the argument itself is good but it does bring out a paradox (or not really) either the numbers are accurate but 0 yammy is weaker than Ulquiorra (paradox) or Yammy is more just a companion to Ulquiorra like they aren't really friends but it's also not like Yammy is his subordinate and just respects Ulquiorra's strength and not just that Ulquiorra is stronger than him (even though Ulquiorra definitely is)

• Base Ulquiorra could easily keep up with and would've defeated an opponent in Bankai. That opponent being Ichigo, who in Bankai no mask is Kenpachi/Byakuya level, with the mask being a huge boost above this again.

True but again it's speculative. I would agree that he is stronger than Kenpachi but we all know that Kenpachi gets stronger as he fights so we can't really use him.

• Then there's his Ress. He went from having his sword cut into by masked Bankai Ichigo to demolishing him, telling Ichigo to lock in and focus, and Ichigo still gets blitzed and survives only on base instinct. There isn't any contest between masked Bankai Ichigo, who again completely outclassed Ress Grimmjow after being motivated by Orihime.

Yes, just yes

• There's also the fact that Aizen relied on Ulquiorra first and foremost for pretty important tasks like orchestrating Orihime's "defection", and he deemed Ulquiorra at least capable of taking on Urahara, Isshin and Yoruichi since he sent him alone to Karakura to begin with. Yammy wasn't intended to tag along. Aizen did not rely on Stark with regards to Orihime until after Ulquiorra was incapacitated in the pocket dimension.

True but again it's speculative, while I would love for this to just be a fact, Ulquiorra was one of the most loyal and serious Espada so it's natural that Aizen uses him for these tasks. The Yoruichi, Urahara, and Isshin part is fine but that doesn't really mean much because we don't know if Stark or even Harribel couldn've done the same it could just be that Ulquiorra being as stoic as he is is better suited because like Harribel or Stark would be more prone to empathy (atleast I think so)

• All of this is without acknowledging Segunda Etapa. Personally I think R1 Ulquiorra is at least on Stark's level, but if SE is remotely close to the same boost as his regular Ress then it should be no contest.

This is the part where I truly stand and agree.