Vilka är de 2 mest kraftfulla enheterna för att slåss mot varandra direkt?

Medan det inte slutade i en 1v1, hade Melkor vs Ungoliant en kort 1v1. Melkor var en Vala, och därmed starkare än en Balrog som bara är en fallen Maia, och vid deras strid var Melkor rädd för hur mycket makt Ungoliant hade för att sammankalla hans Balrogs med hans skrik. Ingen av dem vann seger, Melkor blev sårad och Ungoliant flydde, men det finns inte många enheter kraftigare än de två i hela Arda.

EDIT:

Som begärts i kommentarerna, här är citatet, men det nämns inte särskilt rädsla:

Then perforce Morgoth surrendered to her the gems that he bore with him, one by one and grudgingly; and she devoured them, and their beauty perished from the world. Huger and darker yet grew Ungoliant, but her lust was unsated. 'With one had thou givest,' she said; 'with thy left only. Open they right hand.'

In his right hand Morgoth held close the Silmarils, and though they were locked in a crystal casket, they had begun to burn him, and his hand was clenched in pain; but he would not open in. 'Nay!' he said. 'Thou has had thy due, For with my power that I put into thee thy work was accomplished. I need thee no ore. These things thou shalt not have, nor see. I name them unto myself for ever.'

But Ungoliant had grown great, and he less by the power that had gone out of him; and she rose against him, and her cloud closed about him, and she enmeshed him in a web of clinging thongs to strangle him. Then Morgoth sent for a terrible cry, that echoed in the mountains. Therefore that region was called Lammoth; for the echoes of the voice dwelt there ever after, so that any who cried aloud in that land awoke them, and all the waste between the hills and the sea was filled with clamour as of voices in anguish. The cry of Morgoth in that hour was the greatest and most dreadful that was ever heard in the northern world; the mountains shook, and the earth trembled, and rocks were riven asunder.

Kampen mellan de 2 mest kraftfulla enheterna var före Melkogs första fångst. Efter att ha gömt sig i Utumno's djupa gropar gick Tulkas och brottade med honom och slängte honom.

But at the last the gates of Utumno were broken and the halls unroofed, and Melkor took refuge in the uttermost pit. Then Tulkas stood forth as champion of the Valar and wrestled with him, and cast him upon his face; and he was bound with the chain Angainor that Aulë had wrought, and led captive; and the world had peace for a long age.
The Silmarillion: Chapter 3, Of the Coming of the Elves and the Captivity of Melkor

Tulkas var den största fighteren i Ardas historia, fruktade av Melkor själv, och Melkor var den största av alla Valar. Detta var verkligen en kamp mellan de 2 mest kraftfulla enheterna i Ardas historia.

Jag tror att Tolkien flera gånger kallar Melkor / Morgoth den mest kraftfulla som skapas av Eru, den mest kraftfulla av Ainur, den mest kraftfulla av Valaren, etc.

Därför skulle det mest kraftfulla möjliga paret stridande vara Eru och Melkor / Morgoth.

Så jag föreslår att det mest kraftfulla slaget skulle vara:

1) Melkor / Morgoth vs Eru, om alla de äldsta dagarna anses vara Morgoths uppror och figurativa "strid" mot Eru.

2) Morgoth vs Tulkas, som i Edlothiads svar, om det måste vara en bokstavlig kamp och om Tulkas är kraftfullare än Ungoliant.

3) Morgoth vs Ungoliant, som i Daishozen svar, om det måste vara en bokstavlig kamp och om Ungoliant är kraftfullare än Tulkas.