SPOILER ALERT
So you may pretty well know with all the pre-releases and teasers ,that goku will be getting a new form. Well according to some sources and artwork released by producers this new transformation will be shown in episodes 111-113. sso that would be around 22nd to 29th of october. According to teasers it seems pretty bad ass and super awesome .
So,what caused Goku to get this transformation ? ........ SPOILER ALERT...........
Seems like the super pumped up and yet to use his a ounce of his Energy "JIREN" has been ordered to start the onslaught . So seems like the God of Universe 11 has ordered to kick Goku out of the ring , so the Pride troopers start to engage with Universe 7, in turn Goku and Co. group up and start their confrontation. But since Jiren is so powerful ( by the number of times he is shown as super strong by the writers and producers) Goku decides that nothing less than a 10X Kai-o-ken combined with Super saiyan Blue would be enough to battle him.
So Goku goes all Red and Blue ,but seems like even this is no match for Jiren as all attacks are DEFLECTED. Now since all pride troopers have some kind of special powers I guess Jiren's power is to deflect attacks or related to it. So coming back to topic, Goku seems obliterated by Jiren but then something sparks and Goku turns to his new form.
But according to titles of upcoming Episodes and thier explanation I assume this Form change is not immediate but slow , so probably it would consume 2 Episodes for Goku to turn to his new form.
Well in this period Hit faces off against Jiren and Probably Vegeta also gets his much deserved Lime light.
Episode 111- Hit vs Jiren, Airing Date- October 15th
Episode 112- Vegeta’s Resolve!!, airing date October 22nd
Episode 113- Combat-Loving Saiyan Battle, October 29th