Mecha War: Starting from Gundam OO

Yang Hui, who inexplicably traveled to the Gundam OO world, became a child and a member of the [Barren Bear] family.
With the monkey version of the system with countless flaws, Yang Hui is determined to change all the regrettable tragedies.
However, when he thought everything was over, he discovered that it had just begun.
(PS: Infinite Streaming, there will be spin-off characters and mechas, but it will focus on the main storyline. The early storyline will focus on Gundam, and later on, super series and fantasy series will be added.)
Multiple female protagonists, some magic changes.