MTG Salvation

Thank you, you guys! Didn't expect a reply so quickly. This is my first post and will take note to use card tags next time

I was wondering for example, I had a creature I wanted to cast instants on during combat,lets say my creature was the attacker. I cast mutagenic growth, then another mutagenic growth, then temur battle rage and finally to clear the path an apostles blessing. All on one creature for that combat step.

Is this legal? And if yes, how does it work?