How often are the tantrums occuring? Sounds like a very wearing situation. I have a strong willed child too, I know!!
I had a stubborn one, my middle son. He'd say "why can't I _____ 100 times after being told why. Why CAN'T I ________. Ugh, it was waring!
So we'd say you can say that 5 more times to my face and after that you can only say it in your room where I can't hear it. Go ahead, say it, Why can't I ________. Say it. Okay, good, you still can say it 4 more times. Say it. Good. Keep going. He wouldn't ever get to the full 5. ;D
When he'd tantrum like what you're describing - not a loss of control, he was completely in control - we'd say okay, you have 3 more minutes to scream and yell. Good keep going. If he'd wane a little I'd say go ahead, you can still scream for a minute and a half.
Say it matter of factly like you're saying how many hits he can take at a pinata or how much time there is left at recess. No taunting, no yelling, just informing.
I hope this works for you. My son never attempted to hurt anyone, it was just screaming or asking the same repetitive question.