Heck, I'm going to be honest anyway, since this is my own space. This is your fair warning to not proceed if you don't like to see negative opinions.
I find I have different tastes than other people. Those second Ultramen, the tradition that was started by Ultraman Agul? I don't find them to be so wonderful. In fact, I often wonder what they are doing, hindering our pure-hearted heroes. I've seen people say these secondary Ultras should have gotten their own shows, but I disagree. Trust me, they would be less interesting if they don't have milksop main characters to contrast with.
...Okay, so I'm too blunt. I don't think the main characters are that bad. In fact, I like them, if not outright love (except Mebius; I love Mebi). I don't actually dislike the secondary Ultras either, but I still feel these characters get more credit than they deserve. Just because they are dark and broody (don't get me wrong, I'm shallow and usually love characters with those traits) doesn't mean they're "cool" or "badass" (they are, but really, not to the level some people make them out to be), or more "trustworthy." What kind of a hero you are if you get pursuaded (a kinder word than the one I want to use) so easily by bad (or not-so-good) guys. Agul by the supercomputer, CRISIS. Tsurugi/Hikari by Arbs. Justice by Deschereron something (not sure of the spelling, or even if I have the right name; it has been more than three months already since I last saw Cosmos Vs Justice).
(Ah, yeah, they are not perfect, they made mistakes, etc. etc. etc. but if that's the case, don't be high-and-mighty and look down on the heroes who actually never get tricked that easily. I'll say the main heroes forgive these characters way too easily; I would hold grudges--but then again, I'm not a hero people depend on to save the world.
...I suppose I want to see some groveling. I live for it. I don't like the main heroes not giving these characters any hard time for all the trouble they've caused, though, to be fair, it's not the same amount. I think Tsurugi's trouble is probably the smallest. And Justice's and Agul's are about the same scale. Only that I feel the heroes take the word "good guys" too far sometimes.)
So this post is not really about Justice, after all. And of the three secondary Ultras, I actually prefer Justice the most. (Not sure if it's because Justice is clearly superior, or Cosmos is just the weakest hero among the three main heroes. Or maybe Justice simply doesn't have too much screen time to annoy me. And I like Justice fine in The Blue Planet since he/she is helping Cosmos (Justice claims that isn't done to help humans, but I still think that is Justice protesting a little too much). Justice's ambiguous gender certainly helps too, since I'm favorably biased toward characters who can be seen as both male and female. And actually I guess Justice is like that because of some kind of balance/order he/she has to maintain.)
I'm not ignoring all the good things the secondary Ultras bring to their respective shows, but, in the end, it all comes down to I'm not too impressed.
...I still think I shouldn't post this. A two-thirty in the morning post never exactly comes out good for me.