Yes I know this is the 1001 thread on this, but I believe I need to say it. Let's look at the facts:
Kakashi as of DB III had a 3 in stamina. Kakashi has used:
1. Rarikiri x3
2. Raiden x2
3. KB x2
4. Earth Wall x1
5. Kamui x5
This seems like a-lot of Jutsu, but look at Sasuke. Sasuke had a 3.5 in Stamina in DB III and during the Kages summit used:
1. Chidori Ksunagi x4
2. Chidori Nagashi x1
3. Sharingan Genjutsu
4. Chidori x1
5. Stage 1 & 2 Susano'o for extremely long durations of time
6. Amaterasu x3
7. Enton x3
That's a-lot more than Kakashi has done in this fight so far. Now your saying but Sasuke is a pure blood Uchiha and has more stamina. Which is true, but Kakashi has shown over the time-skip that via training with Sharingan he can mitigate the extra drain it has on him from not being a pure blood Uchiha, without having to raise his stamina. Kakashi has been training his MS in battle the entire Time-skip, same way Sasuke trained his MS. So it stands to reason that he would have lessened some of the extra strain he recieves from MS from being a non Uchiha.
So with that in mind Kakashi's performance can make sense for someone who has a 3 in stamina, but hey just to make things even more copacetic Kishi can simply have Kakashi increased his chakra to a 3.5. Than even another Kamui usage and some other Jutsu could make sense. And Kishi gives characters .5 increases to their stamina or stats all the time off panel, just go look at the rookies increases from DB I to DB II.
So it's hardly impossible that Kakashi increased his stamina by .5 since DB III and that would be an easy explanation for his performance. Heck that's probably what Kishi is thinking when drawing these panels that he'll just give Kakashi an extra .5 in stamina in DB IV.
I'll grant you if Kakashi continues to spam MS like 3+ times or starts spamming a bunch more heavily draining Jutsu plus MS, than we'd need some explanation to justify such a large increase, but right now the increase i'm seeing is plausible if we account for Kakashi's training in battle with MS & potentially increasing his stamina by .5 since DB III. So this isn't the time yet imo to call PNJ or whatever.
interesting discussion. What do you think?