If China goes to war then Pakistan will follow. If China goes to war with India, the US will definitely go to war as well. Russia could do so too. Eventually it wont matter if China wins, we will be isolated from the world, trade would be close to 0, oil supply would be cut off, etc, so on and...
Not all of PLAAF assets are located on the Indian borders. Defending your territory and attacking anothers is a different story. Eventually the PLAAF would overwhelm the IAF, but not after taking massive casualties and then the US will intervene, after which the war will be lost.
I hope to god...