Sorry for my wack sleeping schedule where I wake up at like 3
As for Legend's durability, I wrote a note on the page. If people can tell me what parts of that fail to properly explain his dura I'd like to know so I can touch it up.
Legend's durability is based off how he automatically shifts into a breaker state when he's going to be damaged, which absorbs almost all the energy of the attack. The deeper in this state he is, the faster he is. However, he also loses cognitive function, eventually just not thinking and being KO'd. Behemoth's Low 7-B attack hits him so hard that the tiny percentage that doesn't get absorbed is still enough to one shot him, and he'd have to go really far into it to absorb it and would still be unconscious.
This also means that if he's already partially breaker'd, like if he needs the speed or regeneration, there's a lower threshold you'd have to reach to push him into the unconscious mode. We see Leviathan one shot him, and Legend mentions that's not the only time Leviathan's done that, and he also wasn't exactly waiting around to tank the Alexandria clones from Echidna when he was dealing with two of them and using the breaker mode to give himself enough distance to shoot at them. Furthermore, repeated attacks in a short enough timeframe would be better against him than on normal durability, since if he's not given time to recover he goes further and further into the breaker state to not die.
Against the Titans, Legend's shown suffering waaaay more bodily harm than ever before. His upper body is cleaved into by a titan, his head is chopped through, at one point he's badly hurt enough he needs to breaker far enough to just be laser prism bombarding the battlefield, etc. The thing about this is that all the times he's one shot by an endbringer or whatever, he suffers no real physical harm from that and he's all fine and pristine when he's back up. This leads us to the conclusion that against the Titans, he's forcing himself to stay conscious by not shifting as far and consequently not being able to absorb damage as well. Why would he be doing this? He has to fight like, four titans at once most of the time. Against the Endbringers, it's tons of capes against one thing, Legend can be out of the fight for a while and things won't instantly go to shit. Not so much against the Titans. Legend's one of the only people able to do anything to them, there's not as many capes, capes themselves can turn into titans, and the Simurgh is involved. Legend going down would be disastrous, so he doesn't and even remains in the fight while regenerating.
Now, I don't think he'd assume this random fight to be like the titan situation. He has two teammates, there's not ostensibly some reason for the world to end if he's out of the fight, there's no Simurgh, and within his own setting, he's got more offensive power than basically everybody and doesn't just treat every rando criminal as some threat he has to stretch himself out as thinly as possible to deal with. Repeated High 8-C attacks or a High 8-C attack at a bad time should momentarily down him, from there it's on the enemies to attack him while he's down before he gets back into the fight. He's likely to be using the breaker state too, as he normally does. I'd argue that it counts as an amp from his normal flight and as such he'd use it here to cheat around the equalization rules, but if it doesn't it would just be kicking in when he's moving at top speed anyways.
As a final note, keep in mind that there's the high 8-C end on the titans that's not a possibly one, since only Cineral would 100% scale to her own feat for now.
