Thanos has never been one to be reasoned with. Steve doesn't even try this time. It's a waste of breath he'll need if any of them are going to survive. The only thing stopping Thanos from achieving that self proclaimed goal are the three of them. Right here. Right now.

A quick glance to either side confirms that Tony and Thor are in position. The air positively hums with electric energy Thor is controlling. The soft whine of Tony's weapons coming online is all Steve needs for a signal. They charge in as one. Steve's had enough practice fighting with the others to know to keep his shield raised as he charges forward. Ready to deflect anything Thor or Tony casts toward Thanos while he closes the distance. His boots crunch into the scattered debris as Steve leaps to knock the mad titan off his balance, only to be thrown back bodily enough to cover a good twenty feet.

The soldier's rolling back onto his feet immediately, averting his eyes lest the light show that is Tony and Thor unleashing havoc onto the battlefield blind him where he stands. Every blow Tony or Thor takes only adds to the anger surging through Steve's limbs. The injustice of Thanos coming back here and now to take their victory away from out of their hands again is too much to bear.

Natasha didn't give up her life for this.

Steve spits dirt and blood out of his mouth then he pushes himself up again. His hurled shield knocks Thanos off his aim to spare Tony a grisly blow. They can't afford to lose anyone here. This is all they have left.