Ruling
 

Here is the situation I have a N-1513 in a team and my opponent has N-130 in a team. my opponent passes I go J-848 making N-1513 the user and the target N-130 he chains J-969 making N-130 the user and targets N-1513 and I chains N-1513's effect. Now I know chains resolve backwards now the question is can I still resolve J-848 effect despite I made N-130 a standby ninja bc of N-1513 effect? Keep in mind that I do understand that if there is no user the J-848 fizzle but if that's the same way that N-130 has to be on battlefield for J-848 to resolve then I totally understand just trying to prep for chunin that's all.

If I have N-1513(that already used his effect) and another ninja and my opponent has N-130 that attack this turn, can I choose N-1513 to be discarded by N-130 effect despite that he is getting discarded by his own effect?

j848 would not successfully resolve because the target is no longer valid. The target of j848 must be a Ninja battling the user and Baki is no longer battling against Danzo because you used his effect.

The attacker would apply their effect first. Then the blocker.