This is what the concerns are about with modern bibles.
KJV
Isaiah 63:3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
NIVR
The Lord answers (notice this addition here, 'the Lord answers' foot note, this is mis-guiding, a corruption)
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
These verses below, as you can see, from the KJV, expressively flows as one individual, indicating this is NOT God:
Isaiah 63: 3-7
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
4 For the day of vengeance is in mine heart, and the year of my redeemed is come.
5 And I looked, and there was none to help; and I wondered that there was none to uphold: therefore mine own arm brought salvation unto me; and my fury, it upheld me.
6 And I will tread down the people in mine anger, and make them drunk in my fury, and I will bring down their strength to the earth.
7 I will mention the loving kindnesses of the Lord, and the praises of the Lord, according to all that the Lord hath bestowed on us, and the great goodness toward the house of Israel, which he hath bestowed on them according to his mercies, and according to the multitude of his loving kindnesses.