Why does war arc sm naruto have so much more chakra than pain arc sm naruto?

I ask this because war arc sage mode naruto is able to do freaking multi shadow clone woth rasengans, and use alot of rasenshurikens while pain arc sm naruto cant. Is it because he has more chakra, or what? If so, how did he get so much more chakra, in so little time? (The War takes place a week after pains invasion).

Plot, many characters were much stronger than what they had previously shown during the war arc.

@stormking1221 said:

Outside of Choji and Sakura, not really. Most of the other character seemed stronger simply because they really never had a time to actually shine during the other parts of part 2.

I assumed that while Naruto's clone couldn't drawn any more of Kurama's charka to transform into KCM, he still had enough to change a huge amount of it into sage chakra.

Training and plot like a lot of other shonen characters

plot+main character+Uzumaki traits

Because he now has Kurama actually helping him and giving him chakra instead of being on lock down. He's also able to continuously gather in and gather quicker senjutsu when in BM mode.

@thevivas: i mean before he went BM. When he was stealing chakra from kurama he used alot more rasengans. I guess i shouldve specified which war arc sm naruto.

@glory84: He still had Kurama's chakra in those instances via "stealing" it, though.

@thevivas: yeah true