For Example in First person; when i jump and fire, the Fire Montage Will Play ignoring the JumpStart Animation State, how can i merge any Montage With the Current Animation State (Not Blend)
You need to look into Animation Slots and categorizing your AnimMontages in Slots. You don’t have a specific problem here, I think you just need to view online courses in UE’s website or some tutorials. Basically in your case, the Fire action could directly fire an event that plays a montage. That montage would belong in say the Fire slot or probably something like UpperBody (names are custom not something official). In your AnimBP you would then add a slot node in your graph after your cached poses. It’s not too difficult, but it’s chunky topic and you have to cover some ground in your learning.