In years prior, it's been kept pretty hidden how certain actions interact with each other. This may be changed up in the future, but here is a somewhat ambiguous priority order:
High Priority > Most actions (Blocking > Redirecting > Delaying > Buffing > Protective/Healing > Damaging (Attacks and actions that deal DMG) > Actions taken after damage step
If an action is high priority, it will be mentioned in the action details. Some characters also have passive effects that are independent of this priority order. There are definitely some things that may be handled differently depending on how they directly interact, but this is a pretty alright guideline for how actions will interact with each other.